Why do Atheists always compare God to Santa Claus?

No. There was no Santa Clause. There was a St. Nicholas..... the person Santa Clause is roughly based on, but no, there is not a fat man in a red jumpsuit with a big beard who laughs "ho ho ho" and has flying reindeer and lives in the north pole with elves. And there is no bearded man in they sky who created everything including evil for no reason except for to entertain his narcissistic needs.