I am not sure the disabled analogy holds. I agree with wheelchair ramps because being disabled is not a choice. However, using a “disabled” browser •is• a choice. One my business has decided isn’t worth supporting and can use the time to add features that the majority of users want.
I don't think it is a choice for many people, for example:
If you are using someone else's device where you cannot install anything.
If you are using an older device, which may need JS disabled for performance reasons.
If the browser you're using has special accessibility features that other browsers don't.
If you tried to install another browser, but were not able to.
There are many scenarios, some which I may not even be able to anticipate ahead of time.
My framework's basic features: account registration, posting, commenting, voting, and filtering, are all supported on mainstream or once-mainstream (1% or more market share) browsers released since 1995, to my knowledge, with and without JavaScript.
If I'm able to accomplish this pretty much by myself with a bit of elbow grease, I can't help but think that it's only laziness and excuses which prevent someone with more manpower from at least providing something like mbasic (but not broken like mbasic) to all users, especially on informational read-only sites.