Back in the day, when F2 first came out, I can't honestly say I much noticed any of the excesses that game took. Fallout's always been a little tongue-in-cheek, after all. F2 probably took things a bit far in some places, but I think in other areas they did a very good job with what they had to work with (let's not forget that game came out only a year after the first one, give or take...) At the time I was playing it, I was just glad to playing another Fallout game so soon after the first one. And there were enough upgrades, revisions, and overall polish that in general I was easily able to overlook some of their other questionable liberties that they'd taken.
Still, everyone's entitled to their opinion; and it's not like the inherent "worth" (or lack thereof) of Fallout 2 is something that anyone's going to be able to empirically argue. Some people aren't going to be fans of it. I imagine there's likely a fair amount of people who only enjoyed playing Fallout 3, after all; and didn't really care very much for either of the first two games. There's probably even some people out there somewhere who think the only game that ever got it "right" was Fallout: Brotherhood of Steel.
I do have a couple of things I disagree with in the OP, however. First off:
"a wild west town," isn't something that I can see as being a negative point considering this game. There's actually always been quite a lot of parallels between Spaghetti Westerns, and the Post-Apocalyptic genre overall. Take the first Mad Max movie, for instance. Take away his Interceptor, and put everyone on horses; and it wouldn't have seemed terribly out of place as a Western revenge movie.
Also:
"a stew pot of creative ideas with no attempt to create a cool, immersive fictional universe... just a "hey, let's do this" mish-mash scattered across a map." I'll easily concede that point. It's a common criticism of Fallout 2 that it contains (probably too many) winking nods to the fans, fourth-wall breaking, and out-of-character comments. On the other hand, I don't think they set out to create an "immersive" world; in the same way that Fallout 3 attempted to do that. I have to find it hard to fault a game company for failing to accomplish something that I don't really think was high on their list of priorities in the first place.
Fallout 1 and 2 (to me, at least) were about giving weight to your character's actions and decisions - to give the illusion that literally anything you did in the game was going to have some larger consequence at some point (even if it wasn't realized until the end credits.) The idea wasn't necessarily to create a living, breathing, open world for the player to inhabit in the manner that Fallout 3 (and Bethesda games in general,) was.