To be honest House of M and Decimation are those sort of "events" that haven't aged that well. Another pair of year and they would be forgotten completely for good or bad(because it was not all bad stuff but alas). I think it was more a reaction to the excess of use of "mutants" albeit removing it from the "toolbox" of writers did not lead such awesome original character as planned. Infact i can't recall no character created after decimation worth remembering (some good reboot but no new character or memorable villain) well wiht few exception of course.