Why Ruby on Rails Won't Go Mainstream?

Reading Cedrick Beust’s well-argued post on Why Ruby on Rails Won’t Go Mainstream, and Ted Leung’s thoughtful response, with one of the points being the lack of an IDE, now so important to mainstream corporate developers, I’m wondering why that’s an obstacle that won’t be overcome. I’d think that ActiveState would be all over this, or someone would hack up Eclipse support. (One of the other arguments, that Ruby is too hard for PHP and VB programmers, doesn’t hold too much water once you get the IDE support. Microsoft has had some trouble getting VB programmers over to C#, but the momentum is clearly going in that direction. I’m not going to touch the argument that Ruby programmers have the arrogance of Lisp and Smalltalk developers who remind us that they’ve solved all our problems years ago, if we’d only listen. It’s clever, but I haven’t seen that myself.)

This is an interesting argument. What do you think?