Game researchers don't ignore all Chess-like games that are more difficult for computers. It's just that they've met with very, very limited success in Go. Combined with Go's relative unpopularity outside of southeast Asia, this means you don't hear about it very much.
For example, according to Wikipedia, a computer actually beat a professional Go player for the first time in 2008.
I think, from the viewpoint of a mathematician, there has been more progress in solving Go than in solving chess. http://math.berkeley.edu/~berlek/cgt/go.html shows some progress on generic Go endgames; I've never seen something similar for chess. It all is either a smart exhaustive search, or the use of heuristics that humans think can be used to value positions. I am not aware of any research on the validity of such heuristics.
Because of that, I think chances are we will solve Go before we solve chess in the mathematical sense (at the same time, I think chances are effectively zero that I'll live to see either happen). Yes, chess has a much smaller search tree, but it is inconceivably large to start with, and its rules are ugly. That means that any mathematical breakthrough will likely have lots of ugly special cases (even ignoring rochade and en passant). Go, in contrast, has a much simpler structure.
Sure, perhaps with a huge handicap or on a 9x9 board. There exists no computer that could ever beat any professional go player in an even 19x19 game, even if you gave the professional as many beers as he could drink.
Wikipedia was apparently talking about a handicap match. Still, it's very telling that 2008 was the first time a computer beat a pro even in a handicap match.
In this case, they were fairly reasonable handicaps -- six to eight stones, though certainly large, is not unheard of. You could see that kind of difference between a low-level and a high-level amateur, for example.
Sure, it's not unheard of, but it's still huge! It's extremely hard to become six or eight stones better from that level, and by all appearances, it represents an enormous gap in ability. The most talented and smartest humans take years of constant study and practice in their teens and 20s (at the height of their cognitive power) to go from 2d or 3d amateur -- the strongest programs -- to become a high-dan professional. Further perspective: Various professionals have remarked that they believe the best humans are only about 3 handicap stones weaker than God.
Consider this. Perhaps you play chess; David Levy's famous chess AI bet was that no computer by 1978 could beat him, a chess international master, in a match (I don't know his exact strength, but presumably 2400-2500 Elo -- much, much stronger than an expert!) Now, in 1978 the best computer could not beat him in a match. But it did win a game, and draw a game. However, it took nearly another 20 years from there before a computer could beat the world champion.
But Go computers, relatively speaking are not even as good at Go as the 1978 computer was at chess. The equivalent of a 2d amateur at Go might be a 2100 Elo human at chess, a strong expert; certainly not an IM! So it's not obvious to me that Go computers will be at a world-class level in a shorter timeframe than 20 years. Indeed, I believe more effort has gone into computer Go circa 2010 than had gone into computer chess circa 1978, so it might be reasonable to expect progress to continue even slower.
So it's not obvious to me that Go computers will be at a world-class level in a shorter timeframe than 20 years.
Don't get me wrong: I agree with you 100% on this. I'd more likely go further and wager against that happening. Go has an absolutely silly branching factor, no solid method of pruning, and no straightforward position evaluation function. Material doesn't work nearly as well as it does in Chess, and the sheer amount of information contained in the board makes the "mean value of this board position in past grandmaster games" approach completely infeasible.
My only point is that researchers are, indeed, making progress. It's just very limited.
For example, according to Wikipedia, a computer actually beat a professional Go player for the first time in 2008.