Fielding stats: is it back to observation?

There once was a time when we actually thought we could tell if a player was a good fielder by simply watching him over the course of a season.  Then fielding stats went beyond fielding percentage and assists into the wild blue yonder and into what seems like a constant state of flux all the while insisting that the current stats can homogenize themselves into runs saved and wins above replacement and equivalent to batting numbers.

I have the impression that fielding stats are creeping back into the realm of observation to which I ask: isn't that what we were doing all along?  You know, we pretty much knew who could make spectacular plays and who knew where to play to avoid needing to make spectacular plays and who messed up too many routine plays and combinations of the above.  Not to mention the fielders on our team we did not want the ball hit to in a clutch situation.

I think the new old idea is to evaluate plays based on degree of difficulty, which is pretty subjective: cue the Romanian judge in the Olympic ice dancing competition.  This, of course, is also a function of where the fielder is positioned but let's leave that aside for now.  Example: one fielder catches ten pop ups and another makes five diving plays catching line drives.  By simply counting, the pop up fielder has twice the "range" as the line drive fielder.  Obviously, this does not tell us much.  Plus, the pop up guy may be capable of making fielding plays that are more spectacular but he is also better at positioning so he's not required to do so as often.

Maybe most people know how stats are currently categorized but I do not.  Some illustrations of my, and possibly your, ignorance.

Third baseman playing even with the bag:

1. line drive past him on the bag side that lands about ten feet behind him: I guess that's a line drive and opportunity missed
2. same line drive past him on the shortstop side that goes into left for a single: another opportunity missed
3. same as number 2 but this time the shortstop fields the ball on a hop and retires the batter at first:
    - Is that still an opportunity missed for the third baseman and is it still a line drive for him?
    - It must be a grounder for the shortstop.
    - Do both fielders get counts incremented on the same play?

Am I the only one who does not know this stuff?  Or is much of this fielding analytics obscure even to some of its advocates?  Just wondering.