Fully agree that regardless of the name on the bike, it comes down to finish and components.

But that's for people who know what they want as buyers.
A world sport from 79 is nothing like one from 89, even though the name is the same.

But if one intends to fix up and sell the bike instead of parting it out, I think ignoring the brand and model can really hurt.
A Bridgestone just isn't well known around me. I had to talk people into agreeing that it was a legit frame and discuss why as well as the history of Bridgestone making bikes.
That doesn't happen with a Schwinn, Specialized, Trek, etc. Common buyers know those as brands.

I see great bikes by brands that aren't commonly recognized udervalued a lot and I think it's because of that lack of name recognition.