Cereal & Solids

I am in a Facebook group and there was a HUGE debate over when you should introduce cereal. So let me rant. Me personally, my son is 4 months old and I introduced cereal at 3 months. Occasionally he has a little bit of baby food. No solids. Why is this such a big deal to people? If it is not your child, don't worry about it! You can believe what you want and do what you want with YOUR child. Don't make others feel bad for what they're doing just because it isn't right in your eyes. I don't get why this is such a huge debate.