Not every pejorative is racist or ableist.

That was never a claim I made.

If you can't link the word to a disability and its etymology...

You didn't really understand my point that lack of a bad etymology doesn't make a word not bad so I won't repeat myself.

Cracker isn't a slur either.

Again, not my claim. I put slur in quotes and my whole point was that it carries no power in a white supremacist word. So again you're not really arguing against anything I said. These etymology lessons are great but irrelevant.

If an idea isn't based on material realities and lacks logical consistency it is stupid. A person who's ideas constantly have those issues is not intellectually impaired but they are stupid.

You can say this but you don't have any authority over language. In reality, people use stupid for anything. What I'm suggesting is to rethink what you really meant behind the mask of thoughtful and hasty labeling. Was it "uneducated?" Or "illogical" as you say, or simply "I disagree" or "I don't like this." Reminds me of "using I statements" lol.

Another close analogy (though obviously imperfect) I thought of that might aid in you seeing my perspective is how the word "gay" can be used to mean "lame" (I know this itself has ableist history but it's the best word for this purpose of explaining). Instead of calling everything gay and saying "well things and people are gay when x." Put that x part aside, maybe that alone is valid to criticize, but notice how it's insulting to label that with a word used to refer to marginalized minorities. I.e. gay people and "stupid" people.

Stupidity can be cured.

Therefore what? I'm not even arguing against this statement but asking for relevance. Using the race and gender examples again, gender and race are social constructs. They're fluid. You can also "cure" your gender as in gender affirming care. Does that make the oppressive construct something to cling to, uphold, and rely on?

I don't think I'm able to provide anything new here so if you still disagree and are interested, self reflection and organization of your beliefs and knowledge will be more helpful.