I actually voted no to thargoids. I never played Elite or FFE, only Frontier which didn't have them. And still it is to me the best game ever made. I heard dreadful stories of course about the near superior force the thargoids posed.
But I am so sick and tired about uber-enemies in games. Many times have I abandoned a game simply because it becomes too hard. What about games that actually adjust to my skills? Uber enemies usually doesn't allow this, neither by strenght nor by numbers.
Keep the strenght around my level, and the numbers around my numbers (in case I control several ships). Let the toughness be apparent through proper tactics instead. And let there be a general difficulty setting that can be adjusted while playing; sometimes I like having a hard time, other times I just want to play on auto with not much hazzle. Oblivion had this, and it didn't make me feel like a cheater. Had Oblivion had a default (middle) setting, I would abandon it because it simply becomes too tiresome fighting the same fights over and over. Todays games in general are not playable with me because they are too hard. Others will naturally disagree, claiming them to be too easy. Myself being a "lesser gamer" than most, shouldn't I be able to enjoy the game "my way"?

So... No uber enemies that essencially forces me to abandon the game because it gets too hard.
However, I welcome the thargoids as a species that attack and keep the game spicey at times, but don't make it impossible for me to outmanouver, outrun, or fight them off. If they were uber enemies, they wouldn't have problems achieving their goals.
But... This has to come with a story that unfolds throughout the game. Who are they, where are they from, and what makes them so agressive? Have they eliminated other cilivizations in the past? Anything they are afraid of?
Similarly, I welcome other species as well. But also with a story attached; i.e. we have just made contact with another species and things are going grand with trading and knowlegde sharing. Then suddenly they turn on us and starts attacking our outposts. Then a story to figure out why. Did we trespass into holy areas? Did they become enslaved and forced to do so, if so by whom and why? Please stay away from those horrible "what happened to my father" cliched stories, get some real inspiration by reading some Tom Clancy novels where the apparent is a lot more complex than at first glance.
Yes to Thargoids and other species as communities and even enemies.
No to Thargoids as uber enemies for the sole sake of being uber enemies (which is what I assume the poll was really about).