Mastery 6 and 7 could have gone like this...

They really want the the crafting to catch on don't they. You should have needed points and a certain amount of s rank matches to unlock. Acquire somewhere between 50 - 100k in mastery points while getting 3 - 6 s ranked matches after level five. But I suppose that would have been too much like right. And yeah, a different reward would have been cool for reaching it. I was willing to play for level five but I will just let 6 and 7 come by organically. Sadness is at my door step.