mythic is just one of the various difficulties available, it's not like blizzard impose to raid it, peoples willingly thrown themselves on mythic lured by the reward and then burnout because it require enormous effort to clear it.
LFR>Normal>Heroic>Mythic you can freely chose one, is mythic to much tolling? Then scale down to heroic, the only thing that can be considered blizzard fault is to have supported, for many year, the mentality that the true endgame is only mythic.