In the end, it's mostly the fault of the journalist, not the PR/publisher(s).
I'm a
for an European gaming website (which I shall not name for obvious reasons). I've had my fair share of PR events, previews and such.
During one of the previews, we dined at an expensive restaurant with the PR guy from a publisher I will not name (again, for obvious reasons).
It's fun and all, but at the end of the day, I just care about the game and I write my opinion about that game. Sure, dining at a fancy restaurant is fun and all, but it shouldn't cloud your judgement.
If they want to give me free food, that's their decision. It's not hard to still write an unbiased (although every review is subjective because of OPINIONS) article after getting all sorts of things from them.
TL;DR: accepting PF gifts etc doesn't make you corrupt, it just depends on the integrity of the 'journalist'