ghosting

Jenn • 37 year old woman trying to keep things in perspective.
I matched w/ a 37 year old "guy" through a dating app and we hit it off for about 1.5 weeks. He was funny, observant, thought I was fun to talk with and told me he looked forward to our messages. We even exchanged cell numbers. I really started thinking about dating him in real life. Then, 3 unanswered correspondences later, I finally decide to give up and I'm left feeling like a fool and that my time has been wasted. 
This was my first real attempt at dating after a breakup 2-ish years ago. I'm at a new job and feeling confident in who I am and my accomplishments so I figured I'd give it another shot. The problem is that I've changed for the better but the boys haven't. Now, I could not be more frustrated and deflated at the idea of dating and I'm feeling like it's no longer worth it. 
Why, in this day and age, are grown ass men taking the cowards way out and ghosting (abruptly stopping all communication)?