Suppose your moral intuitions cause you to evaluate worlds based on your prospects as a potential human - as in, in pop A you will get utility -10, in pop B you get an expected (1/m)(-n) + (m-1/m)(-9.9). These intuitions could correspond to a straightforward "maximize expected util of 'being someone in this world'", or something like "suppose all consciousness is experienced by a single entity from multiple perspectives, completing all lives and then cycling back again from the beginning, maximize this being's utility". Such perspectives would give the "non-intuitive" result in these sorts of thought experiments.