In addition to what others have said, this usage is very common in the CTF world. "The challenge has no solves", "We just got the first solve" etc are very idiomatic. It would actually look weird to me if this was "solution".

These examples that you're calling "verbs as a noun" are standard grammar. You can't just invent simplified rules about a language and declare it wrong when the rules fall apart.

They’re shorter.

Why so pedantic?