What's missing, I think, is a question that is not seeking explanation, but improvement. You are not seeking justification of actions, you are identifying an opportunity. This opens up for both an answer starting with "Aha, you might think that, but actually..." and the question "Huh? What is X? How could it be used here?"
Hence, I like
> Could it be made simpler by using `sshd`?
> Did you try `sshd`? This seems like it might be a good fit.
If you get to "Why didn't you just...?" not only have you questioned their competence, but you've also undermined your own competence by allowing them to proceed with work they didn't need to do and/or may have to redo.
"I was wondering if `sshd` would work here. What do you think?"