What tony said...
"If you don't like it, change it" is not about getting flawed rules out in a hurry, it's about ensuring the customer knows the game is flexible and that it's ok for them to change it. I still see this as one of the primary advantages of rpgs over board and computer games. And I like it - if something doesn't work with my version of the setting, I'll change it anyway, but it's nice to have backing from the designers.
Yes, some designers seem to use this as an excuse to avoid playtesting, but please don't generalise that to all of them. It's extremely unfair - the vast majority put a lot of effort into playtesting, and it shows. Not everyone trained on the Star Wars rpg team you know! (Or in the early White Wolf lines for that matter).
Jon
"There are worlds out there where the sky is burning, where the sea is asleep and the rivers dream; people made of smoke and cities made of song.
Somewhere there's danger, somewhere there's injustice, and somewhere else the tea is getting cold. Come on, Ace, we've got work to do."
THE DOCTOR, "Survival" (Doctor Who)