I also struggle a little with the "why" question on this issue. Now I just collected my car Friday, but it seems fantastically balanced to me and has just the right amount of power.
To me, this is often the motoring equivalent of a 24 handicap golfer buying mizuno blades. He would be far better spending the money on some instruction to improve his skills before buying clubs that he is not equipped to handle.
ps no reflection on anyone here since I don't know what level of driver anyone is, just a general musing on peoples quest for more and more horsepower.