You are being reasonable, but only after you pass a certain quality level of musician in my experience.
As an engineer I can tell exactly how good a musician is typically but how easy they are to mix, with monitoring demands being a tell-tale sign of what my night is going to be like.
Many younger musicians especially in the pop circuits have grown up depending on monitors and never had the experience of playing without them. As a result you will get them not even thinking like this. On the other side of things, it is interesting to read articles from bands like Pink Floyd that describe monitors on their stage as a 'virus' that spread from additional musicians they brought on to eventually encompass the stage as they needed to compensate for additional stage noise from the monitors....
Yet when I get bands in that are used to playing without monitors or with minimal monitors, and used to balancing themselves acoustically, and listening to each other on stage, my life on the console becomes SO much easier. But for many musicians these days that is the exception rather than the rule, and they haven't ever really played in such a situation to know HOW to play in that situation I think.
But then again I am just an engineer giving my 'outside' perspective on things.
PS I am still of the mindset that someone should have been minding the mix to be able to help with your monitors to, don't get me wrong.