I'm the registrant of a few keyword gTLDs.
Some industrious folks have bet considerable money on the idea that keywords, as domain roots, are a real value proposition. Ergo, we now have .vacations, .bike, .builders, .camera, .agency, .cleaning, .clothing, .holiday, .holdings, .insure, .promo, .singles, .WHATEVER.
I have a hunch that the new model is likely to benefit the existing holders of keyword domains. Why? How? By focusing the netizens minds on the idea of keyword . . domains.
This will be a test . . but there's a VERY LARGE sample of folks who may now "test" for keyword domains as a result of this new paradigm.
I'd call this an added incentive to build.