So, I do not understand what is wrong with having semi-established Bachelor Nation couples come on BiP. BN loves love-story successes- they are victories for the franchise. Also, the canoodling and the drama is why we watch.
Sure, it sucks for Natasha and she handled it like a boss, but yeah, as Pieper said, it is a game. Here on this forum it is categorized as a game show. As others have pointed out, the franchise is so incestuous. (See, e.g., Blake H.)