Evil overlords are evil because they get to have GREAT fun, like randomly killing off underlings for no reason. They get to throw people into pools of deadly Piranha, and the like. They get to have GREAT fun!!! And then, eventually, some bastardly hero comes and kills off the overlord, ruining the fun.
But, really, how many of us can say that we had all that fun until we died?
Do you want to live a boring life and die at 80? Or a fun, fun, FUN life until you're 30?
Come my overbrethen!!! We shall rise up and crush all who oppose us!!! *
*Note: Until some punk with a sidekick or sidekicks comes and kicks our butt.