This is actually the most logical reason to be upset by this situation.
I won't go into the merits or lack thereof of 120 Hz as that horse has been beaten to well beyond death at this point.
But, what I think Apple fans or Apple non-fans need to wrap their heads around is this:
Apple, as a company, is no longer marketing to tech enthusiasts. Apple is not interested in producing bleeding edge technology. Steve Jobs had a vision of smartphones and computers as household appliances. This vision is coming to fruition. A side effect of that vision is that new potentially unreliable technology, that comes along with compromises like say, diminished battery life, will be shunned in favor of old and predictable technology. Because, fundamentally, that is what the vast majority of consumers want. When you go shopping for a microwave or a stove or a washing machine do you always check all of the tech specs of the machine you want? Or do you, like most, buy something that looks appealing visually from a brand you trust, at a price you can stomach. Like it or not that is how people shop for smartphones.