>>robbie+(OP)
Someone else in this thread mentioned the "boiling frog" effect. Personally, I'll keep using Reddit until they remove support for old.reddit.com. Then this frog is out of the pot!
Looking at one of the subs I run though - old.reddit.com accounts for 5% of total traffic. Whilst 5% is not nothing, it's also not really all that much. I doubt they'd notice much impact even if half of the old.reddit.com users left.