I agree. The main reason for inheriting would be to change the default from auto to stable by setting it on the root, but that can be achieved with a * selector as well, and other cases seem much more likely to be decided on a scroller per scroller basis. And as you said, the force value inherits particularly poorly.
Btw, the original discussion on inheritance is minuted here: https://lists.w3.org/Archives/Public/www-style/2017Feb/0059.html We were on the fence about inherited vs not, with some people leaning one way and some leaning the other, but nobody feeling very strongly. But that discussion is prior to the introduction of the force value, so I think it makes sense to flip.
The CSS Working Group just discussed [css-overflow-4] scrollbar-gutter should not be inherited, and agreed to the following:
RESOLVED: Do not inherit by default
The full IRC log of that discussion
<dael> Topic: [css-overflow-4] scrollbar-gutter should not be inherited
<dael> github: https://github.com//issues/5231
<dael> florian: Way back when initially drafted the propery, discussed if should inherit. people didn't seem to feel strongly. Arguement that won is set it on page was nicer than universal selection.
<dael> florian: Phillepe (?) noticed force value does not inherit nicely b/c creates gutter on non-scrollable. Setting on whole page in general is a bad idea. You should onlys et on elements where it matters.
<fantasai> +1 to non-inherited
<dael> florian: Suggestion is switch to non-inherited. Makes sense and I'd like to do that
<dael> florian: Effects layout so inheriting things that effect layout is good
<dael> ??: Agree florian
<dael> Rossen_: Objections?
<dael> Rossen_: Prop: Do not inherit by default
<dael> RESOLVED: Do not inherit by default