It does seem to get worse as you get older, when I was a kid I was disgusted by how my father would have his regular morning ripper contest because I was never all that gassy, but as you get older you start to realize it just starts to get worse. I've always been one to be discreet but the occasional girl I've dated has been just as loud and leaky as any guy friend I've had so the whole thing doesn't really bother me anymore.
Now burping on the other hand, I admit I'm a bit of stickler about. I've always been able to control burping and at the very least keep it at a level where it's barely audible so I get annoyed when people just let it rip right there in front of me. But what really pisses me off is when there's no "excuse me" immediately after, I've often said to friends "What do you say?" when they do that, I'll often get a sheepish "excuse me" but they've come to do it as a reflex around me now which is in thier best interest.
I just think it's rude, a little bit of etiquette never hurt anyone and it's definetly a lost art that I do appreciate.