lol, that scenario is basically 20% of TT
. While of course such a radical thing will succeed in keeping you honest, will it actually improve your OTB? Not unless you need more "hanging queen" patterns. It's just not realistic -- if you attacked a queen, it didn't move, and mate wasn't threatened, you wouldn't suddenly forget or not want to execute your threat.
There are positions where a quiet move, increasing the pressure is better than a direct sac; those are good, because they're much more realistic.
Yeah, I agree that's a hazard with those things. In fact, it would be good if they threw in a few where the obviously implied idea doesn't work (just to sort of keep you honest).
On the other hand, I can remember a situation on TT where a queen was hanging. And I said, "Well, the solution can't possibly really be RxQ, so I'll look around for a while to find something better." I finally shrugged and--seeing nothing else--played RxQ. And that--rather absurdly--turned out to be the solution.