In order to attract the mainstream audience games need to be easy, if developers don't do it then most people will hate it and thus not buy it. There are some exceptions to this obviously, like the Soul's series.
One of the problems I usually face up with games is that they are "difficult" (the real word should be frustrating) for the wrong reasons: bad camera, bad controls, action commands (God I hate this things so much) etc. this has been around since the NES days but I feel like more games suffer from this lately, many of my deaths in video games are because of bad design choices and not really because I suck at the game (again there are exceptions to this rule), when I fail at a game it should be because I did something wrong, not because the game did something wrong.
There's also the type of "hard" games that simple put all the guys shoot at you at the same time, that imo is a really bad design choice. Devs probably just increase the accuracy of enemies AI to make it feel it's harder, but in reality this is just frustrating. This part typically applies to FPS when to put them on hard difficulty.
Edit: also too many checkpoints, seriously some games today put a checkpoint every 5 seconds >.>
Nintendo and PC gamer
