[howenterprisey]

Two different systems; on the mod side there are two different UIs (one to set each) as well. Yeah it's weird.

[neilv]

I'd guess nobody sat down and said "Here's the target demographic profile for the new UI, so let's rework our messaging, people!" It's just a funny accident of maintenance over time that the result looks like that.

[zahlman]

Each subreddit's mod team gets to style the subreddit (within some limitations). There's presumably a separate set of style rules for the main and "old" sites; and the latter is legacy that most mods (and most users) have not even thought about for years. (Probably most current users have joined the site after the switch and never seen the "old" domain. I'm honestly surprised it still works at all.)