I don't support them, but I find their philosophy interesting, and am curious to know if their plan would actually work.
Oh it would work but that would mean the end of the physical world. I think they are interesting background wise too but if you really think about it you do not want them to succeed.
I therefore think that Beth will never make the Thalmor joinable; they cannot succeed as that is the end of all plus the fact that there are very few that would side with them.
I hope a future TES game will be on Summerset Isles and is about restoring the political balance there. I hope the Dominion stays though(but more democratic) and we will not return to the time Summerset was an Imperial province (thanks Tiber Septim). This was such a blow to the Altmer I blame this on top of the Oblivion crisis for the Thalmor uprising.