While it's well known in our circles that a contact machine like Ichiro will never generate as many runs created per game as the big boppers like Jim Thome and Adam Dunn, Ichiro's skill set is far more unique.
The guy broke the single season hits record, and he's *averaged* 226 hits a year. The guy has a career 36 percent hit rate on balls in play (30 percent is league average) because he gets down the line so fast, and he's got Vlad Guerrero's arm on a 5-9, 172 pound frame.
There are a lot of big power guys who get on base, and those are the ideal players to have if you want to score a ton of runs. But the Thomes, Dunns, Giambis, Delgados are all pretty similar. There skill sets are incredibly valuable, but not remarkable. The degree of difficulty of what they do is less than that of what Ichiro does, even if the easier feat is the more valuable.
If you want to build a team, go with the big boppers. But some feats of baseball artistry transcend their mere contribution to winning - hitting in 56 straight games is no better for your team than hitting in 30 straight, going 0-for-1 with two walks, and then hitting 25 straight, but the degree of difficulty makes it great. Similarly, hitting .400 with an OBP of .430 isn't any better than hitting .300 with an OBP of .450 (something that Todd Helton does every year), but it's still something that we appeciate because of how difficult it is to do.
Winning is the foremost goal, and while Ichiro might not contribute as much as Thome on that front, his artistry is more unique - and that might be more important and better for the sport.