non-technical PMs are the best. They don't try to do things they can't, they take our word wrt complexity of implementing things and tradeoffs. And they are mostly women, which brings an extra layer of much-needed balance.
A counter point - I've worked with Developers who have told me a load of BS. In those instances I knew it was BS because I was quite conversant with that bit of knowledge (this is not to imply that I'm some astounding developer; but anybody with some basic technical knowledge would have realized it was BS).
