Obviously, it is not feasible to develop every single feature request people have. There are various reasons to say NO most of the time, and this article give good advice on how to argue with requesters. I highly recommend it.
I usually differentiate between visionary product managers, leading the product and the team strategically, and the not-so-visionary product manager, caring more of details and drawings nice slide decks. Both types actually exist and both types seem to be actively sought: Recruiters have a very distinct idea of who they search and how much to pay them.
Of course, no recruiter actually admits that they search an inexpensive PowerPoint worker.
However, maybe I was wrong with the assessment of the two types: Roman Pichler points out in his post Matters: Big vs. Small Product Owners that different maturity levels require different types of product managers. True point.
Obviously, the greatest ability of a product manager should be to say NO (instead of Yes, or Maybe, or Later). Now I stumbled upon this exceptional post that explains all the reasons why someone might suggest a feature and why it is still important to say no. Highly recommended!