MMA has a WAY higher turnover of fans than normal mainstream sports. The UFC as a company also does a horrible job of honoring their legends and overpromoting the current guys as the "best ever" to the point that no one feels special so it's not that surprising that he faded away. Most fans of this modern cycle of mma probably don't even know who Randy Couture is which is an even bigger travesty. Majority of people will watch for one era, then their favorites will get old and go on losing streaks/get swept under the rug, and then lose interest. Only a small, niche portion of the fandom are true fans of combat sports in general and don't tune in just for names... personalities draw attention, the sport itself doesn't.
Being successful in WEC (and not the UFC) + Being successful in a small weight class that wasn't established in the mainstream yet + going on a losing streak + getting buried by the UFC for a rape related joke + all of the above = vanished from discussions.
PS: Torres beat Mighty Mouse.