What's the logic behind having kids outside marriage?

Question

I absolutely don't mean this to be judgmental in any way and I'm totally asking out of curiosity and a little confusion.
 It seems like lots of couples make the decision of having a baby before they're married (and I'm talking about planned pregnancies not accidental ones) and I don't understand why. If a couple isn't married, that means they aren't sure that they wanna spend the rest of their lives together (unless they don't believe in marriage-as far as I understand). So why would a couple bring children into the relationship if they aren't sure they wanna stay together to raise the children?
Again, I totally don't mean this to be judgemental. I just want to understand. 
UPDATE :Thank you everyone who responded to this. I understand this better now. I think my confusion came from not realizing that a lot of couples are fully committed and have great and stable relationships but still choose to not get married for various reasons (family, finances, not believing in marriage, and other reasons). I thought there were only a few couples like this but seems like I was wrong.
 Please feel free to keep commenting your stories and reasons so me and others can better understand having kids outside marriage.

Answer

Some people don’t want to be married. Some people don’t feel it’s super important, but most importantly what other people do isn’t your concern.

Answer

I have 3 kids and currently on a fourth. We’ve been together for 11 1/2 years and for me marriage is nice and a good end goal but I personally don’t mind having kids because I’m not waiting for marriage.
It’s not that I don’t value it but it doesn’t control my every move.
We’ve managed to be together starting at 15 so I’m not really worried about him leaving. It’s a personal decision that we aren’t married and I’m ok with that

Answer

One, I'm not religious so I'm not worried about "sinking"
Two, I'm engaged and have been planning a decent wedding (nothing over the top, but nice) and i don't feel like dropping $30k on one night
Three, we bought a house together with both of our names on it which is still a pretty big commitment and have joint accounts, etc. 
Four, I dont need to have my name and my SO's name on a piece of paper to say we are commited to each other. We both know we are committed and honestly I feel like marriage doesnt have the same meaning it used to generally speaking since divorce is common now.
I could keep going but I'll stop here

Answer

My husband and I met in our early 30’s. We knew we wanted to get married, other circumstances made it so we would have to wait two years out of respect for other family members getting married first. We wanted them to have their day and not compete with them. We were engaged for two months and found out we were pregnant ( for the second time, the first was ectopic and I almost died). We were over joyed. Because we were in our 30’s it didn’t matter to us which we did first. Marriage is never a guarantee, and when we did marry, our son was 4.5 months old, nothing between us changed. It was a great celebration of our family. In my opinion it’s a very judgemental question. It is very common now for people to have babies first then get married. Marriage is no guarantee of stability for a child. If your relationship is strong ( married or not) that is stability. At the end of the day, our marriage didn’t change us and I wouldn’t have done anything differently.

Answer

I had a child and got married, now we are divorced. We both co parent and raise our child the best way possible. I am currently with a guy and we are having a baby in February, we arent married, but plan to be. Just because you have a child together doesnt mean you have to be married or even in a relationship for that matter.

Answer

Me and my partner live together and are extremely happy, we're also 20 and 29 and don't think spending thousands of pounds on a wedding right now is plausible. We don't feel like we need to get married to show how much we love each other,  however we do think that bringing a child into the world is the ULTIMATE way to show love. It is something we want to do together in the late future when we have a few grand spare but it in no way shows we don't want to stay together or that we love eachother any less than a married couple. To us it's just a piece of paper.

Answer

I don’t think marriage makes much of a difference when it comes to having a baby. I’ve seen men from one night stands step up and be better fathers and involved more than some women’s actual husbands. I think marriage is a wonderful thing considering the fact that I am married but I also think it’s a thing religious people and judgmental people love to throw up in other peoples faces to make them feel shameful and what not! At the end of the day if you’re pregnant and having a baby a piece of paper shouldn’t make much of a difference with how that child’s raised and loved!

Answer

Not being married but being together and having children doesn't make you love each other or the children any less. We don't need a piece of paper saying were married to love each other or our boys. I was married once and the divorce was horrible . We have talked about getting married later in life and may possibly but we are happy how things are now sometimes marriage changes all that and not always for the best .

Answer

Personally...
I used to feel like you when I was younger
But I’ve since had more life experience and feel differently.
 
I met my fiancé at almost 35. Knew each other was ‘the one’ for us for life.
Found out I had low ovarian reserve. So we did things in the opposite order, I didn’t want to miss out on motherhood by waiting. We have a 1 yo boy now. Very much planned.
 
We want our wedding over in Ireland where he is from and where his family is, and my good friend and her family is.
I also didn’t want a quickie rushed wedding before ttc. I still wanted to have the elegant, meaningful wedding I’d imagined for years, also didn’t want to do it while pregnant with a bump. It would have felt like we were getting married because of us expecting. Now, we’ll get to have our son at ours. And I see it as celebrating our love, and reaffirming our commitment and strengthening our bond. Not as making the commitment. The commitment is already there, well and truly.
I have no regrets, and have never questioned his commitment to either of us. He’s a very hands on dad, and a supportive, attentive fiancé. That’s more than I can say for some of the husbands I’ve read about on here, and even some husbands in my own extended family.
A man is either committed and supportive or he’s not. Marriage doesn’t change that.
 
If I’d held out for a wedding first, then I might have missed out on motherhood, and it would have been an enormous regret.

Answer

Because not everyone sees marriage as the be all and end all. Some people see a baby as more commitment than a marriage

What's the logic behind having kids outside marriage?

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