The simple answer for you. It got profitable and marketable.
+1. And now the industry (or at least part of it) is in the tricky spot where there is real money to be made, but mostly only in the mainstream.
Fact is that it is expensive to serve small niche markets. The hardcore community is way too small (and probably too price sensitive) to make much of a profit.
As a result the big players all aim for the mainstream market - or (in case of the less imaginative ones) 'artifically' try to make it a bigger portion of the overall market by pushing mainstream products but calling them 'core' (whatever that means...).