They do care a little bit, seeing as they tested the waters recently (https://www.wowhead.com/cata/news/classic-mega-realm-consolidation-blizzard-looking-for-feedback-338412). Whatever they got from that, it seems they decided to just let the players decide – again.
But maybe it’s an unsolvable problem at this point. It’s like Bigbazz mentioned in a separate thread; pve servers have more alliance players and pvp servers have more horde players.
One solution could be to open a new server and enforce the SoD-ruleset on it, but there are a ton of other issues associated with such an idea. Will people be able to transfer to it? I can imagine there are a lot of players who do not want to roll a new character, but who may want to play on a balanced pvp server. Will they be forced to reroll? Necessary evil?