Most stealth games (to not talk in absolutes here), even the best of the best, are based in a "trial an error" aproach from the player.
But this is what i find weird. So, IO designers take some decisions to make the game less trial and error to gamers (hence Instinct mechanic) yet anyways they get slammed. To top it off, that's a complete optional mechanic for the game XD
The problem with the game is not so much related to say... IO selling themselves or something similar to what happened to Splinter Cell. As i see it, is just that the level/mission design is so inconsistent, you get 1 or 2 interesting levels others are hit or miss. Plus the scale is reduced, but imagine if people nowadays complain about trial and error, what about a level like Shogun Showdown which was massive. Something like it will create a wave of suicides around the world.
But the traditional Hitman gameplay is there, for example, the other day i spend close to 5 or 6 hours figuring out how to ghost play the Orphanage Hallway. Takes a lot of patience, like the old games.