Luckily crpgs have had a resurgence recently and seem to be doing very well now.
As for RTS games, it comes down to time and dedication, most people don't like putting that kind of time. Contrary to the poster a few posts up going on about "special Snowflake" bs it comes down to people not wanting to be as dedicated to games where you have no teammates and requires a lot of time. Personally I've loved RTS games and played a shit ton of SC2 the first few years it was out, I'm looking forward to AoE 1 remake this Thursday as well.