To use your analogy of the writer and the ashtray —

It’s fine that the writer can’t describe an ashtray. It’s not his job nor his passion. He ignores any complexity that can be found in the ashtray because there’s absolutely no reason for him to know.

The problem is that the writer thinks he knows about the ashtray.

When that happens, we can only hope that the writer does not come across too many ashtrays.