<shrug>I was fun as a kid in the 80's, occasionally difficult as a late 80's - early 90's teen but still generally fun and goofy, and have carried that all the way into my 40's, still fun and goofy .. and my wife will agree, occasionally difficult.
I think it's more an us vs. them kind of thing.
I personally love kids, have one of my own, she's awesome, most of her little friends are pretty fun, and I've met many other awesome kids. Met some real POS kids too, I generally found their parents were POS's too. Which explains why my friend's kids are awesome, I don't hang around POS's long enough to meet their offspring.
I have a few DINK (Double Income no kids) friends who seem to think I should be ravenously jealous of their 3-5 nights out a week lifestyles and the fact they can crash a Lexus and not stress about saving for a college fund. They don't seem to realize I was already tired of living the party life 5 or 6 years before I even had the kid. If they're enjoying that life of pickling their liver 2-4 times a week, after their extended money making hours, their Nephrologist will thank them in a few years.
I hosted a 3th grade gaming computer build party for my daughter's friends, two years later half the kids are gamers who are begging their parents for the latest Nvidia cards. I like feeding information to sponges, it's a lot better than dealing with long term employees who don't want to learn a new thing without a pay raise.