Angry Grimace
Two cannibals are eating a clown. One turns to the other and says "does something taste funny to you?"
This. Do a Google search dude. Your friend is just flat out wrong. My buddy has had a RIS kegged since June. I can't even imagine what the argument would be that they go bad quickly in kegs
Because most people who have home kegs just use picnic taps on them which causes them to quickly lose pressure and oxidize.
You also will think it's bad if you don't clean the line it comes from every once in a while and realize the beer that comes out of it at first is just the stale old beer that's stuck in the line from the last time you used it.