So, of course, the nice gentleman who asked an opinion was quite upset at me for returning an "honest" answer.
Could I have been more diplomatic? Yep. Could I have ignored the request, knowing how I would answer after reading his synopsis? Yep. Do I care that I hurt someone's pride? Nope. It isn't what I set out to do, so feeling "harmed" is a them-problem.
What will I do in the future?
Locally when a writer (of anything from novels to school papers) ask me to read something and claims to want an opinion, I warn them up front of my belief in straight replies. I cannot help someone if I have to spend half my time trying to decide the "least offensive" way of responding. Time is something I do not waste.
So, other than when the response is positive, or simply providing an answer, without coloring, I think I will provide a request --
Do you REALLY want an honest opinion, or are you seeking affirmation?