Hey there!
Happy to talk live about this if you'd like. My email is in my profile, and I can speak more in depth[0].
Sorry to hear that your company is ditching 360s in favor of NPS. I've facilitated dozens of 360s across a wide range of companies as a part of my startup, and I can speak without hesitation that when they are done well, they are invaluable in a growth and development conversation.
NPS is a flawed metric for measuring people. In particular, numeric rating systems that have no descriptive meaning behind them are exceptionally unreliable when not run at scale. As an example, we used to run surveys where we asked individuals to rate someone on a scale of 1-10 for a particular skill. It quickly became apparent through customer interviews that every individual had their own definition of what it means to be a 5, 6, 7, etc. You end up with scenarios where you have "hard" graders who use "5" as meeting expectations. You have others who use "7" to mean "average". And then you have others who say "9/10" means meeting expectations.
Another example of faulty NPS is when we attempted to measure the satisfaction of direct reports with regards to their manager. If we ask an NPS style question, we end up actually measuring how much they like their manager as a human being, rather than whether or not that person is actually doing a good job as a manager. There's some data floating around that says that 75% of employees leave their job because of their manager, and not the role itself, and we see similar information in our data. So, oddly enough, someone will respond positively to "Would you recommend this manager to someone else", but will simultaneously quit in six months for reasons related to their manager not doing an effective job.
Lastly, measuring employee performance is exceptionally hard, and I'm unconvinced that you can do it at scale and across multiple departments and organizations using the same techniques. What works for a software engineer does not necessarily work for measuring performance for a marketer, which does not necessarily work for an executive. Putting everyone into the same bucket seems more convenient than effective.
Because of this, our process tends to focus less on measuring people, and more about creating effective conversations on how people can improve. We do this by recommending that companies implement role rubrics[1], so individuals understand what the expectations are of them in their role, and how those expectations shift as one progresses through titles and responsibilities. In addition, we gather peer written feedback on the behaviors that mostly closely are associated with how we work together as a team. These tends to be non "functional" behaviors, and they are fairly universal regardless of industry, title, or seniority.
Unfortunately, both for my company and employees, this tends to not really be a priority for many companies. Managers don't feel like they have the time to do a good job in these areas. Employees appreciate the process, but often aren't given carveouts in their day to actively provide feedback to one another. It basically becomes a time-intensive process that is never a "top priority", so companies devolve to the quickest possible solution to the "objective", which they think is measuring performance, rather than helping employees grow and develop. I'm still fighting the good fight though, and there are plenty of companies out there that take this stuff seriously and care about helping their employees grow.
So, in short, no, I don't think you're being cynical. But, what do I know, I just do this for a living :)
[0] wes@eagerlabs.com
[1] https://circleci.com/blog/why-we-re-designed-our-engineering...