Guess people will just have to plan better in advance. There are no first-time gamblers who start after midnight or so..

Not the end of the world.

I believe with many rewards programs you can still sign up and get a card when the desk is closed by asking a pit boss or slot service. Obviously more advanced requests like redeeming an offer might have to wait until the desk is open.

Where I can see this being an issue is if you want your play reviewed for back-end comps when the desk is closed... I've never run into this situation, but if you played late into the night and had an early flight it could come up. I'd guess a pit boss or slot service could still find a host on duty though.

You could always go to a table game to get a new card.

I recently ran into the latter issue when checking out of the MGM Grand. Not even a particularly early departure either, it was around 9am or so and the desk still wasn't open -- I think I have departed other Mlife properties around the same time and had no problem, so I don't know if MGM Grand has more restricted hours or what. But in any case, the check-out agent suggested I call the Mlife desk after I left and ask them to review, which seemed odd but did work, and they refunded the value of the applied comps to my credit card.

Yeah, this has become annoying a few times for me and my later evening arrivals (7-8 pmish) as most CET rewards desks seem to close at 8pm on weekdays and 9 or 10pm on weekends. You Just have to adjust your schedule accordingly i guess. But can be annoying when you want your comps/vouchers/whatever else printed out and the desks are closed.
Really, how much are they saving on wages by not having at least 1-2people working the desks until midnight or later. As for cards, many times you need to line up for a new card or whatever and during the daytime hours the lines are insanely long and SLOW.... which most people don't feel like waiting.. so the casinos are missing out on getting new players playing with their cards at their properties.