Romulus and Vulcan never were particularly important for the Star Trek Franchise, as I see it. They just served as a backdrop to tell stories.
Romulans and Vulcans, on the other hand, were and are important, and they still are around aplenty.
But perhaps it's a difference in attitude as well. I enjoy the stories told in the Star Trek universe (and the themes they bring with them), but I'm not necessarily attached to the attributes (read: the characters) required to tell those stories.
It's similar when I go to some concert of a world famous musician or artist. I enjoy the music they play; I don't (necessarily) adore the artist.
I never adore musical artists because they are humans and have faults just like me and everybody else.
However, there are some of them I have a certain admiration for because they seem to be good and likeable people or because they have overcome some addictions or other problems.
There are also some real a**holes who I don't admire or even like as persons but I might like their music.
So I think that you and me think the same there.
As for Romulans and Vulcans, the destruction of their home worlds will affect their future appearance and importance in Star Trek and I don't think it will be in a good way. I do find it totally unnecessary to come up with the stories in which their planets were wiped out and I simply can't accept that.
As for series like Star Trek and such, there are two things which I highly value:
1. Good storytelling with well-thought and well-explained events.
2. Likeable characters.
TOS, TNG, DS9 and VOY (at least for three seasons) had that.
I might lose the interest for a series if the quality of the stories starts to decline after two or three seasons.
I might also lose interest for a series if characters I like disappears for different reasons, especially if I don't get an honest and believable explanation why this and that character isn't in the series anymore.
There are three series in which I took an immediale liking to all characters already from the start: Voyager, NCIS and CSI New York. With all other series I have liked and still like where the characters have grown on me during a certain process, such as DS9 which I found OK from the start but became better and better the more I watched it due to the writing and how the character developed.
As for Voyager, I didn't like the way Kes was dumped and the pathetic explanations for that. I could actually live with the changes in NCIS even if I didn't like some of the changes due to the fact that the new characters were quite OK. But when main character Gibbs left, the series sort of died for me because it was the last of the original characters who was left and all of a sudden I realized that "hey, what's left now is just second hand characters" even if the storytelling still is quite good.
Watching NCIS now is like watching a Beatles without John, Paul, George or Ringo with Jimmy Nichol (who temporarily replaced Ringo as drummer during a tour due to Ringo having his tonsils removed in 1964) as drummer plus three unknown musicians. The music might still be good but it won't be right without the legendary originals.
So characters are very important to me.
There are also examples of sereies I've dumped because I found them downright bad, such as DSC where I found the characters bland and boring, the stories boring and the "Klingon Ninja Turtles" horrible and ENT because I found the characters boring, the stories weak with lots of screwing up of established Trek history and because I was dead against a retro series then.
Then of course we have the infamous
Stargate Universe which I ditched after 4 episodes because I found it so incredible lousy but started to watch again since a friend of mine told me that he had fallen asleep twice while watching it. It became a joke between us after that, sort of: "Finally Friday and what do we have tonight! Staaaargate Universe!"
Oh me and my twisted humor!
