It's difficult to evaluate anything aside from stated public opinion, unless they have a managerial track record (the problem there being that you are then evaluating only a pool of selected and self-selected managers/coaches/etc). In general, I do not have a high opinion of professional athletes publicly stated opinions on value evaluations for their chosen sport - I don't think they, as a class, are any better than the average fan of that sport at judging the value of players in their sport.
There are of course athletes who are actually good at judging value, and some that are particularly bad. Being able to skate or run or throw or swing a stick that is shaped a certain way at a projectile shaped another way doesn't really speak to your ability to spot what is actually important about that sport and evaluate that dispassionately among your peers. That, however, doesn't necessarily apply to being able to evaluate who can skate/run/throw well - the actual physical skills of said sport.
I don't necessarily have faith in an athlete's self-evaluation, either - certainly I don't apply any real importance to their ability to self-evaluate simply because they are a professional athlete.
Basically, I would summarize my thoughts as "I don't put any faith in someone's opinion about a sport just because they played that sport at a high level."
It's a really interesting and unique take and I won't fault you for that. I think it's fair to question most of what is publicly shared by anyone, unless that person has consistently spoken in a way that turns out to be pretty accurate and direct. For example, Grier has shown himself to not really mince words, so when he says something, I think it's worthwhile to take it at face value, That's a little beside the point but it could also apply to players (players of the past like Boyle match up to this, self-evaluation or team evaluation was actually very insightful and interesting to listen to).
If you're talking about value as in contract value, I think that's a fine position to hold. Players aren't meant to be experts in the business side, cap implications, market value, etc. etc.
I however would disagree with you that a player playing on a team is universally "no better than the average fan" at judging player value during play. Even mediocre professionals understand their sport far better than the vast majority of fans, including their particular role, the details around skills, and the details around systems. I believe this, but it sounds like you don't believe it. For the players we're talking about to make it to the NHL means they absolutely must be able to do more than just "skate, swing a stick a certain way, etc" because there are 10x as many players who were basically as skilled as them that weren't able to make it. This is especially true of players like e.g. Pavs or Dellandrea or others who are completely replaceable from a skills/physical standpoint but have nonetheless carved themselves out roles in professional settings.
The same is true and I think very well established that in order to succeed as a professional, you really do need to have a growth mindset and an ability to adapt your game. Players like Sturm were all-stars their whole lives and have to learn how to carve out a role playing very differently than they did for most of their hockey career. That takes a lot of growth/learning mindset, self-evaluation, and the ability to be coached by others. These are not easy skills.
I'm not going to convince you though, and that's fine. I generally do put more faith in someone's opinion about a sport just because they played that sport at a high level. It doesn't mean I think they're always right, but I consider their position and points and POV more strongly than an average fan who may not have ever been successful even at a high school level. Being a successful athlete is far, far more than just being athletic.
