I think it's possible to trust someone's judgement even if they haven't left a lot of (or any) feedback ratings yet. The OP's approach is just way too blunt.
I might trust my doctor to have good judgement on what medication I need but I wouldn't trust his or her judgement to leave feedback to someone on this forum.

What if the feedback is about Lauda's pill addiction?
Ok, I'll get my coat.
The doctor doesn't even know who Lauda is, nor the knowledge needed to make Lauda send a signed message to verify Lauda == his patient!