I will unpack a little and answer each part.
Why might one want that thumpy upright sound? Well you mention jazz and bluegrass (but omitted rockabilly) and those might be reasons. Others might just be looking for something different/unique. A metal band with an upright would get some notice for it; and all attention is god if you are trying to be recognized (as they say, just make sure you spell my name correctly).
There are lots of tones people get out of basses that I don't care for. But that is their sound and I get it. For instance, my teacher plays ultra-clean. I like to have some hair on my sound. I like the crunchy tone that Geddy and Myung get and I am aiming somewhere in that range. McCartney often had a thumpy sound which may be a combination of string choice and the amps that were available; I don't think it was homage to the upright tone of his contemporaries/predecessors.
I am not smart enough to play fretless. If I were ever to attempt upright, I would be going EUB and running a pedalboard to get some drive in the sound.
My brother and I are doing Stray Cat Strut (which, of course, has an upright in it). I am playing a thunderbird (with drive) for that; we aren't aiming for a true to the original recreation; we are rocking it up.
I guess I fall on the side of - it is OK to not like the sound of upright. That doesn't make you a bad person; but maybe there are other things that make you a bar person

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Yeah, I'm not a fan of upright. I have no desire to play one. I understand that some people have an opinion contrary to mine.