> They are frequently more prone to shifting as environments change
Never had that experience, myself.
> They contribute less to tone compared to their thick-necked relatives
How can you possibly quantify this, other than to say “well uh, they’re thinner and tone relies on thickness,” which is obviously untrue.
> Thin-neck basses give the impression that their action is higher when compared to thick-necked basses having the same string relief
Lol what?
> Having owned thin and thick-necked basses I don’t find thin-necked basses easier to play (I have average-sized hands)
To each their own. I own both thick and thin neck basses (back-to-front, as I’m assuming you mean) and I absolutely do find the thinner ones easier to play. Your like or dislike of something doesn’t validate or elevate your opinion to the realm of fact.