Because, devs and publishers want to access more and more people to increase their profits. (as usual in a normal capitalist economy) And, lots of these gamers are the type that we call 'casual gamer'. And, these people want only fun, easy gaming, they do not enjoy pain like we used to. So, each day devs came with more and more easy games. (ex:compare dificulty in these titles: Gothic 2 and 3, Morrowind and Oblivion) Old times' unforgiving games are out i am afraid.
I'm debating this question all the time: are my gaming skills were increased tremendously that nowadays non of the new released games can not challenged me, or that i mentioned above?