This mentality isn't unique to product managers. Mobile developers and front-end developers increasingly don't want to work on technologies that are perceived as outdated, or even to work on someone else's code. Everyone wants to list new technologies and greenfield projects on their resumes.
This was one of the biggest hiring challenges at my most recent large project: iOS developers wanted to rewrite everything in Swift. Android developers wanted to rewrite everything in Kotlin. Our web app was already written in React, but the web developers constantly wanted to refactor it to use the latest state management trend. When Hooks were introduced in React, we spent far too long arguing with developers who wanted to refactor all of the working code to use hooks instead.
The bigger problem is that nobody wanted to work on someone else's codebase. Everyone wanted to work on greenfield projects and technologies that would look good on their resume going into the next job. Some of the most talented developers we hired were obviously only interested in using our company as a stepping stone to FAANG jobs (which didn't actually pay much more, but they were more prestigious on a resume so they wanted to switch).
Blaming product managers is an easy out and will likely match popular opinion among people who aren't product managers, but the problem extends to development teams as well.