Middle English: via Old French from Latin privilegium ‘bill or law affecting an individual’, from privus ‘private’ + lex, leg- ‘law’.
In fact, in France privilèges have been abolished during the revolution. And it's not just the wrong word, it's kind of opposite; privilege generally meant the benefit of a minority, but here it's used to describe when the majority benefits, because they are the majority.
Descriptivism allows for expressions like, "To boldly go where no man has gone before!" which is a split infinitive, and an 'incorrect' use of language. If a native speaker would say a thing in speaking, then it's valid. Native English speakers use language in all sorts of ways that would be 'incorrect' -- from jive to rhyming slang to 1337 sp34k to adoptions from queer culture like 'shade' or 'yass'.
Relevant XKCD: https://xkcd.com/1576/
And at least according to makers of the OED, it does not define words, it describes them: https://languages.oup.com/about-us/how-we-create-language-co...
I shouldn't feel guilt because I can walk. But it's important to recognize that my experiences and my abilities might be different than others.
An architect designing a public building with only stairs or narrow doors, or a traffic planner optimizing crossing times for an average pedestrian are cases of failing to recognize their privilege in being able bodied. If, after being made aware of their privilege, they continue to design for themselves then they may be considered immoral by some people.