Well, I happen to be one of those people that believe DMs learning "the hard way" should be standard operating procedure and which having to do so is not bad in and of itself. But I also believe that when experienced players say "X is too hard for new players, the game needs to give them help!"... their experience is coloring what is truly needed for new players, and that new players aren't necessarily the delicate flowers that these experienced players make them out to be when they want designers to make games "easier" to run. But admittedly, that's probably just my biases talking.So when the game tells you "magic items and feats are optional, play the characters you want", it never comes out and says "but there's a price to be paid there, and the DM has to be very careful to tailor challenges to the players". Experienced DM's know this and have their own approaches to the problems. New players and DM's will have to learn the hard way, when that could have been avoided by warning them up front.
I will note that 4E was a game that always gave me the impression that it was designed to be potentially run with barely any DM input because its balance was so easy and even that the game was "bad DM-proof". It literally didn't matter who the DM was... the game could almost be run on its own and worked fine. But to me... that always struck me as not such a great idea. Because new DMs got everything handed to them and it all worked wonderfully, it never taught them how to improvise when they eventually found themselves in a situation that didn't. They never learned the hard parts of being a DM. Which I don't think is a good thing personally.
So I don't begrudge people wanting what they want... I just will push back a bit when they make it seem like it is an imperative that it be done.