Again, heroic is only similarly rewarding if you can fully clear it in one night. If you can’t, then m+ is definitely the better bang for your buck. Regardless if you spam them or not.
How is that any different than someone wanting the healing trinket off Behemoth? They have one option and one try for the week on that difficulty. If you want to run more than one TS that week, you get as many tries as you can stand. Which sounds more rewarding to you?
Whether or not you personally would spam TS until your eyes bled makes no difference, the fact remains that the option is available. There is no option for that in raids.
That is subjective, and different for every class and spec.