Catalan move order

If white plays the Catalan by delaying c4....ie playing d4, g3, Nf3, Bg2, 0-0 first he avoids a number of good lines for black, namely all the Bb4+ lines. Given this move order appears to cut down black's options why don't more strong white players use it? It occurs to me there must be a drawback to the move order, I just can't work out what it is. Any suggestions?

With all the move orders and transpositional possibilties that exist with 1. d4, I'd say there is always the possibility of ending up in a Neo-Grunfeld or Fianchetto Benoni which are fine for black. I play this move order with white, and for me, the question is when to play c4 as white.

You are commiting to g3, before black needs to with e6. White can only really but black under some pressure if the white square bishop is bad. If black can develop bg4or f5, and get a pawn structure with d5, c6, the bg2 isn't doing in much. (It isn't really a catalan either).

You can play for a quick b5 with black giving excelent chances for and equal or even better position with black

1 d4 d5 2.Nf3 Nf6 3.g3 c5 4.Bg2 cxd4 5.0-0 Bd7!?=

As mentioned before, the Catalan, like the Colle; is reliant on Black's LSB remaining behind the Pawn chain.  Hence why it is played after 1.d4 Nf6 2.c4 e6 3.g3 or 1.d4 d5 2.c4 e6 3.Nf3 Nf6 4.g3 and not via 1.d4 Nf6 2.g3 or a myriad of other bad options.

the most direct way to "punish" white for delaying c4 is the b5 line as given by pfren. i have played it as black myself and after doing a lot of research and having little experience, i could say it holds but requires very precise play by black, because white can try this a4 and c4 stuff and also he can try bg5 stuff without an early queenside thrust and black will have to be prepared to the teeth to hold his ground. seemed to me that it is just too much work and felt that all white is risking is equality but black is risking his life most of the time. eventually i decided to go for the bg4 lines instead. i'd say this b5 line is best but better left for when you are really strong. i am not that so i can be lazy and go for bg4 instead.