I'm with you on honesty, and I've certainly seen people tacitly trying to pass off AI outputs as human written. But I think we've reached a point where, in lots of contexts, we can't reasonably assume human authorship by default any more. (We can reasonably want it and push for it! I just mean we can't literally expect it.) So even when we would prefer openness, I think 'lying by omission' is too harsh a characterisation for people who choose not to declare AI authorship but don't actively try to cover it up.

Honesty is the whole problem with ideas like this. If you're the kind of deluded idiot that considers LLM-generated crap "your code", stating exactly how little you had to do with it is not in your advantage. Far easier to maintain the lie.

Nobody owes you any transparency about the way they develop their software.