Let me paraphrase a famous quote...
Doing the same thing over and over again, only to get slightly different results, is still insanity.
...I see it as pure laziness by the developers, to not have a more fleshed out story and variety of level design. What's crazy is they have a lot of people believing they actually put more work into this kind of stuff, merely by adding a few different things you can use as weapons and a few characters to react to a few different scenarios. It's all the more maddening when one of those characters isn't where they're supposed to be when spending time setting up one of the optional kill methods.
My faith in IO went down quite a bit when they cooked up this ways to kill hamster wheel style of play. It's clearly an easy cash grab, and they are definitely charging WAY more than it's worth.