Whether or not people realize it they're absolutely doing some weighted rating in their heads of upside and readiness.
One thing I liked way back when from the original Hockey's Future website was how they had prospects rated by both upside and likelihood of reaching that upside.
So, for example, a forward might get a ranking of 7.0C, which would mean they had a ceiling of being a third-line forward in the NHL, but they weren't likely to achieve that potential (If I recall correctly, 10 was generational talent, 9 was elite/all-star level, 8 was top six, etc, while A meant that they were basically guaranteed to hit their ceiling, B meant they would likely fall by 1, C by 2, etc).
I mean, those ratings were often off by quite a bit, but I did like the idea of the system, at least