[waqf]

The purpose of the trolley problem is precisely to explore the limits of a set of rules (in this case, the "rule" that fewer people dying is better than more, vs the "rule" that you shouldn't actively harm a given person).

It's legitimate to argue in response that those limits won't ever be tested in the real world, and if the problem-poser thinks otherwise then it's their responsibility to come up with a question that can't be gamed.

By contrast, once one picks a set of "rigid rules" as you advocate, then the answer is predetermined and not interesting.

[stale2002]

Spherical cows don't exist in the real world either. Does that make all high school physics questions "useless" because they don't exist in the real world?

Sometime you have to solve the basic question before going on to the more complicated questions.

[eli_gottlieb]

The whole problem is that you don't know where the "rules" came from in the first place, which means the thought-experiment doesn't reveal much about how to generate fresh responses to novel situations.