Those players had an option to raid in previous expansion. That option has dried up for them. These are players that hardcore guilds need, though I get the feeling from your posts that you would be happy if they all just quit and left.
Sadly, if that did happen, hardcore guilds would die rather quickly. Hardcore guilds don't recruit the bulk of their raiders from other hardcore guilds. They recruit from less progressed, more casual guilds. And those guilds recruit from still less progressed, more casual guilds. When the guilds at the bottom start dying out, it causes a chain reaction from the bottom to the top.
Essentially, you're advocating cutting the legs out from under hardcore guilds, and I don't think you've quite grasped that yet.