Half the comments in here boil down to "I would stop using Reddit if they discontinued old.reddit.com" and it really rubs me the wrong way.
It's like saying "Facebook will die if they start charging users to post to their wall".
Like, okay, sure. But Reddit has repeatedly said that they will not depreciate old.reddit.com. They have zero reason to, as many of their powerusers rely on it.
In fact, I don't think Reddit has a history of deprecating anything! Freaking. .compact is still around from god knows when!