If you look to the top of the page, next to your username, there's a number in brackets. Wouldn't it be nice to take that number and buy something real with it? You could, if it was a fun cryptocurrency that had at least a little traction.
I'd imagine certain people could use their Stackoverflow Coins to buy a house!
So what property does Dogecoin have that Bitcoin doesn't, that enables us to do this? The answer is nothing, and Dogecoin is redundant. Might as well use Infinitecoin or any other copycoin before Dogecoin, they are all the same copy/pasted code, with no technical added value and the only effort they put goes to marketing.