What some people seem to be missing here is that no matter your reasoning, alt+f4-ing is immoral. Period. People forget that we are talking about Team games here, most likely an assortment of random players. It is not 1v1, and therefore, it is not all about you and what you want. Ranked matchmaking brings together players that want to play competitively; it should not just be for players who want something very specific, expect everyone who does not play like them to play their way, but deny that courtesy to others.
I hate arena, islands and bf, and usually ban one of them, but if I get placed into a game on one of these maps I will play it because chances are the other players are really looking forward to playing the map, and - since it’s TG - they kind of need multiple other players. I will play maps I don’t like in the hope that others will pay it forward and play maps I like.
I find it unfortunate that this discussion brings out the self-centered egoist in some people. Instead of paying it forward one tries to deny everyone else everything out of fear they will do the same. You have to assume, even when playing popular maps like Arabia, that one or more players are not “one-true-mappers”, and would rather play another map, but will still play the game so that those placed in that particular game can play. That’s what Ranked is all about: not playing a particular map, but playing AoeII, together. If you want specifics, settings, a particular map, that’s what lobbies are for. You can still check the elo of people that join there to balance teams. But don’t go alt+f4 bomb the experience of everyone else because you are too self-important to realize that it’s not always about your needs. Not when you play team games.