I don't think it's argued that these didn't harm the community, so I want to know, which do you think hurt the community more?
I think it's faction/server transfers. Even with LFD, there's still a lot of things in-game in which you have to interact with people on your own server (raiding, guilds, challenge modes, rated battlegrounds, occasional dailies, world bosses, etc), and you still do have to mind your server reputation and keep it good. However with faction/server transfers, it doesn't matter if you have the worst of the worst reputation on your server; troll it up as much as you want, you can simply pay to do it all over again.
edit: explanation added