nexon.net maintenance and update

I'm curious as to why they can't just do both maintenances at once. Would make it a lot less of a hassle in my opinion. Then again, I'm probably missing the reason here.

Normally, changing the website shouldn't require taking all game servers down. Since they are, and for 12 hours at that, I'm going to assume they are also doing some rearranging of hardware or internal network (not upgrading, if they were doing that they'd be boasting of it in the maintenance notice).

The weekly Maple maintenances include stuff like backing up data, processing server transfers and name changes, and such. These things require the network and electricity to be up and stable. It will probably be impossible to do it while the "portal" update is being done. Doing it right before runs the risk of not finishing on time. Doing it right after is risky because something might not be working right even though the portal upgrade team says they're done.
I'm glad they're doing the maple maintenance a day earlier. That means it will be routine and as risk-free as ever.