I've pugged 3 dps chars to +15's within the last 3 months(i fucking love m+). From my experience the only people who have issues finding m+ groups that they are geared for is people who expect to be taken to m+'s that are leagues beyond what they have done before.
Raider.IO is an experience monitor. It outs people with little experience and that makes them angry. Buying a m+15 doesnt mean you get invited into all the +15's you want. Which is actually a really positive system for the people who actually like progressing in m+ instead of just being carried.