@Debbie189 I agree with @Linda108 that the guest's correspondence should yield a better indication of their suitability than their profile or photo, or even their reviews. I don't put any faith in the review system, as my most horrific guests have been well-reviewed. (I do cross-reference to see how the guest reviewed their past hosts).
It's not unreasonable to have doubts about a guest who didn't take the time to complete a profile, especially if you're an in-home host. But on the other hand, the internet is cluttered with quasi-social platforms that require visible user profiles, and I can't blame someone with a private disposition for not wanting to put much about themselves out there when they just need a place to sleep.
If it helps make a decision, ask a couple follow-up questions about relevant details and see how the dialogue goes.