Partly perhaps, but it's a lazy assumption especially given that WoW initially was their first foray into MMO's and as code, policies, and practices become more efficient things get easier. You can see a lot of devs talk about very clunky code that made updating/patching certain things harder that they were able to smooth out over time, and sometimes not.
Classic's new and while I'm not exactly programming literate people underestimate how much the computer world has changed in the last 20 years because their lazy asses still just use the point and click interface with some gui upgrades. It was a much bigger ordeal than tweak a few nipples to get classic running especially given years of network and hardware changes. And as someone who works for an airline where maintenance emergencies are an unfortunate reality you can't always perfectly predict how long a repair is going to take or when it's going to need to be done to avoid a delay. Shit happens.
I'd agree they should at least give a partial credit for the time above normal maintenance hours. But every single one of you acknowledge and agreed that maintenance happens when you booted up the game and it can vary based on the actual needs of the servers. But overall all this crying just reminds me of people who schedule their flights so they arrive 1 hour before their event beings and then cry because weather delayed them 2 hours.
Let's not be dumb here and pretend money is the only factor in play here. Hell you even mention the second one, time. And how a person wishes to spend it whining on the forum or annoyed they can't use a service they pay for is ultimately up to them.