While I understand that -- the fee you pay for changing realms and factions is way too step for me to continue. As of right now, I've quit the game for ~ 2 months because of this and am on FFXIV.The issue for cross faction play isn't necessarily the technical aspects, but it uphends the concept of Warcraft.
Something that would fix this for me is allowing a "free of charge" that reloads once per weekly reset to faction change, race change, realm change, etc. Have a cap of however many characters you can have. This way you can realm change all of your characters one week and faction change them all the next -- but not (easily) abuse the system. I'd even be ok with a 15 day halt on raid achievements to prevent the race from screwing over.
But no, they won't do that. They want that money so... suppose I can't compete up with that as my friends leave / I gain new friends across other realms (usually from M+ or whatnot).