When is highly technical crunch desirable?

[Max_Killjoy]

Depends on the individual.

Some are increasing slope - their sense of fun is directly proportional to the amount of crunch.

Some are decreasing slope - their sense of fun is inversely proportional to the amount of crunch.

Some are upside down parabolic - their sense of fun is at its lowest at both ends of very little and a lot of crunch, preferring the sweet spot vertex of the middle.

That last one would be me.

I want enough crunch that the mechanics "feel" like the thing they're modelling, and that different actions feel different, but not so much crunch that it takes an hour to resolve under a minute of in-character time.

Sadly, industry trend seems to be towards either too little, or too much, crunch. I see too many games now that are either "Roll your Combat stat vs the NPC's danger rating, if you succeed you get to narrate the fight and outcome, if you fail the GM gets to narrate the fight and outcome." or "First, determine the relative advantage from your stance vs the foe's stance, then apply that to your anticipation skill and your perception skill, roll both, and use those results to..."

[NorthernPhoenix]

"When is highly technical crunch desirable?" Personally I'd say it's desirable when that is the premise of the game from the start. A game that sells itself as primarily a tactical wargame or similar should have highly technical crunch.