I don't think it's a problem that they think it's a good idea to locate them in scenic areas. I think it's a problem if they only locate them in scenic areas. There's a need for both transportation and recreational infrastructure, and there has to be balance between them.

And honestly, when they accomodate my route, I'd rather be on a scenic MUP than a functional MUP for two reasons:
1 - I like scenery. And they tend to be fairly quiet, which makes me happy.
2 - Running beside a river means few road crossings. I'd rather ride a slower but steady pace than a stop and start pace as required by regular intersections.

My city has both, and the current push is for more of the functional category. Most of the functional ones now are rail trails, which are, IMHO the best middle ground.