This is no different than any MMO. Even the old ones (EQ/XI) raid content has lockouts your limited to the content you can do per week. The fact that you feel raid quality gear should be thrown at groupers even more freely amazes me. Raid gear should be reserved for raiding alone yet they allow you to collect myth from grouping that puts you in gear on par with raiders.

Your last point I agree with though. Raid gear having no materia slots makes no sense as you don't really start collecting materia until your at the point you start wearing gear that can't use it.