On the question of why would anyone play an RPG when he is more interested in the “G” than in the “RP”:
You seem to think that the currently extant boardgames are complete replacements for RPGs for those people. Since I am sometimes “those people” and play lots of boardgames, I can tell you that they aren’t. No boardgame actually replaces GURPS, HERO System, Pathfinder, or RuneQuest (for instance) as a complex combat and skill sim. And a bit of roleplaying alongside the “G” is fun, too.
Boardgames are great for a shorter, more regulated experience. I have and play Descent, and Clank!, and a variety of other dungeon crawl boardgames. But they do not have anything like the flexibility and tactical depth of a complex RPG and they don’t provide anything like the same experience in play.
You might as well ask why anyone would bother to play GURPS, when Fate is strictly better (since it concentrates on the RP without all that distracting mechanical stuff). The end of that road is pure cooperative storytelling, which is, I am sure, a fine thing. But it’s not a thing for me.
That you (collectively) don’t much enjoy the mechanical elements of a tactically focused RPG is a data point and I suspect a strongly held opinion. But it does not invalidate my experience. I’ll have fun in my own way and let you have fun in yours.
None of which should be taken as anything other than a response to the instant issue. There’s a reason I keep coming back to listen every month.