Well, it's blatanly dumbed down. But one shouldn't mistake removal of content with "dumbing", as these are two fairly different issues, even though they interact together.
Religions, vassalizing, and similar mechanics got the axe we are today bound to see in EACH AND EVERY series of games with planned expansions. Just think of The Sims, everytime they start from scratch with a barebones game and then crank out a buttload of expansions that do what they already did in their previous incarnation, just to bleed your wallet dry.
10 bucks on the table we are going to see most of this content back in the expansions (and as I'm fairly sure to win, at least MY wallet will not suffer as much from the aforementioned bleeding syndrome

).
So, more than "dumbing", this mechanic is just business. As long as customers have no complaints at (re)buying 3-4 (if not 8-10 like in The Sims) games to finally have a full game they already had but with prettier graphics and a couple different mechanics... well, good for the devs and the publishers, I would do the same. Hell, people keep buying each year pretty much
the very same product when it comes to sport games, 50 bucks for an updated DB with players in the new squads and maybe a bit of texture polishing? They
deserve this treatment
The dumbing down rather resides in how what content actually IS in the game is handled. And while everything is much simplier, some things aren't as bad as they might look. On certain things, you're saved from nightmarish micromanaging that certain CIV4 features required, which isn't bad in my book. This lets you concentrate in actually having fun staging wars, and diplomatic relations, and... yeah, and what? Too bad this "advantage" collides with the aforementioned lack of features to have fun with now that your hands aren't tied (and craptastic AI, ok, but that's a whole different issue).
Let's take religions or corporations as an example: I never, ever really bothered with 'em in CIV4 (with the exception of Fall from Heaven of course, religions were something really meaningful and terribly
fun to play with in FFH, completely changing your approach to the game based on what religion you chose). All those missionaries or representatives to train, manually send here or there to spread what they were related to, all for a dubious effort/gain ratio (mostly for dull bonuses that added nothing to the
gameplay per se): not worth my time.
If (when... ahem) religions were to be added in an expansion, keeping this streamlined approach at gameplay, they could actually manage to add their needed flavour and be fun to play without becoming more of an hassle than anything else.
Certain other things, that I like: the removal of tech trading in favor of the research agreements is a nice step forward from the extremely exploitable tech brokering mechanic we had before. It could be more advanced, to realistically depict two civilizations working together
in the same field of research, but it's a start. Embarkment instead of painful micromanaging of transport storage, yay, way to go (though, it's funny how the AI is still dumb as heck when it comes to explore and colonize oversea lands when now it hasn't to manage that mechanic but units can just straightforward walk over water as any respectable messiah can).
There are several instances where this streamlining isn't dumbing down but actually what I consider an improvement in gameplay, it's just even in those instances, well, things are done in an easier way, which is good, but sometimes do too few things, which is bad.
OT P.S. @ afa2000
IIRC, also several good mods for our beloved Fallout 2 were done by Polish and Russian players, especially the latter. I remember almost crying seeing how many features the russian mods had compared to the english ones

Anyway, I don't know how appropriate the comparison is.
Fallwhat 3 was a completely different game, from a completely different software house, which just happened to buy (and controversially at that) the rights for the names and setting of the original two games. Not even a bad game per se, in it's genre, I would say, just nothing to do with the originals, and nowhere near as smart in maintaining the fine irony that permeated 'em.
New Vegas, being developed by many of the old devs, might be a refreshing experience even if it uses the same engine as F3, not really an engine suited for "deep" rpg playing. Let's hope so
