Except you're griefing. Which is illegal.
You logging out makes room for other players.
You are not playing. People who want to play are waiting.
How is it griefing? Blizzard are the ones that put the restriction how many people they will allow to a server before closing it and saying it's full. Blizzard let more people on the servers than what the servers could handle, and now the players are paying the price for it. I'm not on one of those servers though, but I can imagine it would be annoying as hell to have to wait 2-4 hours just to be able to log in. If anyone is griefing anyone, it's blizzard who is doing the griefing. They could have not filled servers to the very limit (and more), and closed them at say 70% in order to ensure these things dont happen. Instead they allow some servers to be over populated to the point where players can no longer log on and use the service they are paying for, while other servers are close to dead. Blizzard put the players and the servers in this situation. And now they balance it by having a queue time for players on high pop server to log in, and making a CRZ system toi give the illusion of dead servers not beeing dead.
A little bit of thinking ahead would have gone a long way for blizzard.
Because you purposely ruin the gaming experience (or the lack of it) of players.
Blizzard are NOT the ones putting limits on their servers, let that be clear. It's the servers themselves and the technology of it that puts it on their servers. If Blizzard can help it, they will.
And the queues have been there for a loooooong time mind you. Only with MoP people came back and such, sure they could have closed the servers at 70%, but if there's room on a server for say 2000 *don't know actual numbers*, then 70% makes 1400 people. Now imagine 900 people having inactive accounts? Whoops.
That's basically what happened.
Also, I will repeat what many, many, many players have said.
Those players KNOW themselves they're playing on a High populated server.
Those players KNOW themselves that when an expansion launches, players come back.
Those players can expect queues, and whether they take action against it is up to them, but they shouldn't blame Blizz for their own stupidity.