"Though we fund all types of startups, we're especially interested in web/mobile applications. We've been thinking about that problem longer than anyone else, and by now can visualize much of the space of possibilities."
This means that they are more comfortable investing in an area where they're the experts. If you're going to blindly apply to a VC without reading their "About" page, that is you being irresponsible, not a problem with the VC.