Let me put it this way. Had Barnes made four more shots, not only would he have more than made up for the 7 points that he "opened up" for Curry and Thompson, but those shots would still be available for Curry and Thompson to still make. Barnes making four more shots, thus putting him in the category of "statistically efficient," something you say is "irrelevant," adds one more point than having him not make those four shots and having Curry make that 3 and Thompson make those other two shots.
Additionally, the Warriors are actually up an additional point on three less shots if Barnes makes those extra four shots, thus satisfying the requirements of potentially being "statistically efficient," something us "stat darlings" focus on. If Curry and Thompson make none of those three shots you mentioned that are still available had Barnes made those four shots, the Warriors are still up by one point, and that's still a better situation. However, if they still nail those 7 extra points, the Warriors are now have 8 more points than your scenario, potentially more if any of those extra 4 shots that Barnes made were 3s.
On top of all of this, had Barnes made four more shots, he'd make even more open shots for other players. There's no way around it. The more shots you make, the more a team will make an effort to ensure that does not continue. That could potentially open up even more possibilities for the Warriors to score.
There's really no way around it. Barnes being more efficient would have been much more beneficial than your point of view that apparently only "those who know the game" can see. Sure, there is still benefit to shooting the ball even if you miss, but you can't argue that a miss is more valuable than a make. Sure, there are instances where a guy may miss a two-pointer, which opens up a three, or maybe another instance where missing a free throw opens up the opportunity for more points, but those instances are far and few between and generally cannot be planned in as a regular part of a game.
