"To be frank I'm surprised GameFreak hasn't opened up a "customize" style of play that does what Smogon does; clearly many people prefer to play that way and don't want to waste time building mons, while others find building mons a satisfying experience in and of itself.
For my own part, I enjoy most the exploration, finding all the wild mons and catching them. That's what makes Pokemon interesting to me. I'm happy to go out and catch things. Others don't feel that way, and want a mon solely because they need it to win.
I don't begrudge them the desire to PokeGen. Why should I? They're skipping something unfun to them, while I still get to enjoy it. That's win-win.
The problem is that people who enjoy breeding DON'T ACTUALLY ENJOY IT. They don't breed because it's entertaining. They breed because what they lack in skill, they'd like to make up for in sheer spare time. They want the end results of breeding to be something they have a monopoly over, so they have competitive/trade leverage.
That's why they're whining. It's not that they've been denied something, it's that when everyone has something they no longer have the power position that comes from exclusivity. Pokegen doesn't take away their fun because they aren't actually HAVING any; what it takes away is their sense of superiority.
It's like someone giving away designer clothes to homeless people, and then a bunch of elitists complaining about it. They only ever wanted something that others didn't have so they could lord it over them, they never wanted it for its own sake.
Which, of course, makes them the worst kind of people imaginable. Seriously, the people whining about Pokegen are the kind of people who just have tremendously ugly personalities in real life."