I have no idea why TOS's writers were so enamored of that particular star name.
I had the impression that the writers wanted to use star names that would be more familiar to the audience. Of course, most of those are the really bright ones, and back in the '60s, much less was known about stars and whether they could support intelligent life-bearing planets. That's why I had to reset my expectations once
I started learning about such things (I got into Star Trek and serious astronomy around the same time, spending my noon hours in the school library reading
The Concise Atlas of the Universe and studying the Hertsprung-Russell Diagram).
For those who are having trouble reconciling the TOS episodes with modern knowledge (or just your own increased knowledge after watching the episodes): If you've read any of the older SF authors, such as Heinlein or Bradbury, have their stories become unreadable now that we know humans can't live out in the open on Venus and Mars, and that there can't be farms on Jupiter's moons? I just mentally shift them into a category of "this used to be SF; now it's more like alt-universe/fantasy, but it's still a good story". If you make that mental shift with some of the Star Trek episodes, you can still enjoy the story, no matter that it's set in what we now know to be an impossible location (I really had to talk to myself about this, concerning Vega...).
Of course, they also said it was the home system of the Orions, which doesn't make much sense either.
A lot of people mistakenly think that all the stars in a single constellation are grouped closely together, when the truth is that the constellation is just an illusion that humans created because our brains are wired to seek out patterns. It really annoyed me every time someone on Doctor Who announced that Gallifrey is "in the constellation of Kasterborous." From which vantage point, in which galaxy?
I don't get why everybody assumes the Preservers are some immensely ancient race from the dawn of time. The one canonical example of their activity that we know of took place no earlier than the 17th century -- since obviously Native North Americans were not in danger of extinction until Europeans began to colonize in earnest. That makes the Preservers a modern civilization, not an ancient one. They're roughly as far behind us as Picard, Sisko, and Janeway are ahead of us.
If their purpose was to save the Native North Americans from the Europeans, why didn't they save
all of them? What made just those few worth saving, rather than all the others, with their wide variety of cultures and customs and histories?
And regarding the speculation that the Preservers (or whoever) had the ability to extend the lifespans of these supergiant stars and prevent them from going supernova, they obviously missed some (Beta Niobe, Yonada's parent star, and numerous others). Keep in mind as well, that when a star is in its late stages, any planets it has will have already undergone profound changes. For our own situation, the Sun may have billions of years left, but life on Earth doesn't. This planet is going to be unlivable a lot sooner than 5 billion years.