If Isometric RPG's aren't favored then why are the Ultima series, Baldur's Gate series, Planescape and Fallout 1&2 considered some of the best RPG's? Why is Baldur's Gate being re-released with extra content and an enhancement after 12 years? Why has Obsidian Entertainment started a kickstarter game which is to be a traditional isometric party based RPG? Why has Larian gone back to the isometric RPG genre? Why do most who have played Divine Divinity and DKS prefer the first over the later?
out of all the games you listed, i do not recognize any of those games apart from fallout, and if fallout 3 or new vegas didn't come out as a 3rd/1st person RPG then i would not know what fallout is, it seems the older generation gamers seem to like isometric, where as the majority of the gaming community will want a 3rd/1st person RPG
Isometric games are best for games like orignal sin, because it's co-op and the type of game you would jump on with a friend and have a good time, an Action RPG, however divinty 2 was not a Action RPG, it was an RPG that got you immersed into the game with a good story and good combat mechanics,open world and a decent leveling system, divine divinty has thus far not grabbed me as well as divinty 2 did.
RPGs should be immersive, not something you just play for fun and spend a few hours a day on it, but something to spend your whole week locked up in your room completing.