Perhaps because their interest is in trading, or mining or whatever? Why SHOULD other players have to play at the difficulty level one group want, when it is quite possible to arrange things so that people play at the level of challenge they prefer?
This shouldn't be an either/or selection, computer games have always had difficulty level options to cater for the varying degree of challenge people are comfortable with - to ignore that because you HAVE to set it at one level for some reason, fair enough, but to set it at a single level when it isn't necessary to do so is short sighted from a commercial viewpoint because you'll alienate people you would wish to retain as customers ... and I think that is currently pretty evidently happening when it needn't.
By the way you get a wry grin about your police response comment - the first time the police turned up to deal with the guy trying to kill me they all got their backsides handed to them, the NPC baddie killed all three cops in about 20 seconds flat then started after my hide again. (I left him to play in that system by himself, mind, at that point).
Dave