Ahhhh, those good old, poorly thought out, late night rants. Heheheh.
Nah. Rule 0 isn't a 3E thing only, but I have noticed that with the sheer amount of splat available, many players seem to come into campaigns as though it doesn't exist.
It's a playgroup thing though, not an edition thing. It happens in all TTRPGs.
I did feel 3E ended up with too much "bloat" though. To offer your players interesting options, the ones they wanted, did become a nightmare sometimes. But you could have perfectly good campaigns with just basic rules, or only a splat or two.
It's probably my experiences with the two systems so far. I played a fair bit of 2nd and 3E, as a PC and DM, and only a bit of 5th.
5th has so far seemed lighter and easier to run, and even the poorer choices don't necessarily ruin a character/group/campaign. The playgroups also seem to approach it from a slightly different angle. Rule 0 is very much in effect from the word go, because it has to be. The rules aren't exactly that tightly worded or definite. This may or may not be a good thing. But it makes players far more forgiving in many ways, with everyone just there for fun, rather than for rules debates.
I do think it also stems from the character creation process. People get slightly more invested in the RP side of things, even at level 1, even when they're looking for and planning for the power options. This makes stuff go more smoothly for some reason. Characters feel more rounded, even when the game mechanics aren't. It provides reasons for actions and situations, that the entire group can understand straight away, so there's less "because I'm chaotic" and more "because I'm a sage". It's easier for some reason.
It's just my opinion of it though. I liked 2nd, 3E, 3.5 and 5th. There's no better or worse system out of them, I just like 5th's flavour right now. It seems "friendlier", even when a lot of that comes from it being more poorly written.