Their mistake was keeping the old interface around at all. If they had just killed it off we would have complained about it for a while and then just moved on.
I only use Reddit from behind Tor, on desktop, so I open a bunch of tabs to amortize the load time, then read them in sequence and close each one as I read it.
If you have fast Internet and a short attention span, and faith in your web browser's back button, maybe that doesn't make sense.
There's 3 new comics per week. It's not like you can sustain a whole website on that.
I don't know, xkcd.com seems to be doing just that.