Quite a hill to die on. If I were to exhibit the same kind of pedantry you are, where a compound noun can have exactly one meaning regardless of context and specialized terms are disallowed, then I'd point out that computer != CPU so your example is irrelevant.

Folks here are genuinely trying to help. "Modern computer" clearly has a special meaning in the context of building a computer from scratch; the term is used in contrast to calculators or specialized number-crunching machines, both of which are computers and are of interest to tinkerers.