I agree with you. I have both live and frozen rats (and Asfs) here. I haven't needed to feed live to any of my snakes, but they come first and I always have a backup. I don't think that is unethical (and I'm not saying you were telling me that, but I have thought out all of these scenarios before I tried my hand at breeding). I prefer to feed my snakes F/T, but that's just my choice. I've learned a few things, had some problems here and there, but I think I've got it down okay.
I will say that I think some people feed live because it's easier for them and they might not weigh all the possible outcomes of that. Either way, I'm comfortable with how I do things, and I have reasons thought out for them (for my situation). We all have our "right ways", and I try to respect everyone's choices... as long as they value their animals and put them first.
It's all good with me.