Oh yes, you’re talking about the “gamers” who’d smash their controller because they can’t beat a level in Crash Bandicoot, those who use some aim help in FPS and rage quit after having been shot 3 times, those who think that EA makes great games (OK I’m trolling for that one)? 
Yea, definitely can’t make a die and retry game for that kind of “public”.
It’s funny, in the late 90s was released Oddworld: Abe’s Oddysee. That game didn’t have any way to save the character’s current position. If one died, one’d have to restart the level (or at least the beginning of the “board”). And Abe would die pretty much every time he’d be hit (or even fall from too high!).
In Abe’s Exoddus, they introduced the “Quicksave” (to perform a “Quickload”, similar to a custom checkpoint). Fair enough (and quite the cool feature at that time), the levels are bigger, more mechanics, etc.
But a few years ago, they released a remake of the former one, renamed New ‘n’ Tasty. And what did they do? They felt the urge to add the “Quicksave” function (that, I remind you, wasn’t there in the original version), because nowadays average (low-tier i.m.o.) gamers start crying whenever the game feels too hard.
People who put their hands on the Dark/Demon Souls saga (for example) know what’s coming at them, and the series is still selling and going despite its nightmarish difficulty. 
One must keep in mind that there is a difference between dying because of their own mistake, and dying because the mechanics suck (heavy character, bad feeling, weird controls, bad camera, funny gravity and so on).
Just my opinion as a long-time gamer, I’m not judging your choices as a developer, I understand that many companies choose to please the target customers to give their AAA games a better chance to reach a wider public and make more money. One cannot please everyone =)
Actually some games provide the player some help if he dies too many time. Like showing how to go through, give bonuses, etc.
That’s an interesting way of avoiding too much frustration I think.
