Yes, in WoW you can choose either PvP or PvE, either way you are playing with others though. And you can't just switch your character from a PvP server to a PvE one on a whim. Yes, you can transfer your character between the two, but it costs like $10, takes processing time, and there are limitations on how many times you can transfer. In ED, you can go from Open to Solo on a whim and without cost or consequence.
If ED would make a PvP server, where you can be attacked at anytime, and a PvE server, where you can only be attacked if flagged, and make each of them separate servers, that would be totally fine. If you want, you could transfer your stuff from one to another, but for a cost and a cooldown associated with it. So instead of Open and Solo mode, we have PvP and PvE mode. I would be fine with that.