I think if you could get to mastery 7 by just playing more, that would just give everyone mastery 7 in no time. At least now you have to choose where to spend a (semi) limited resource that everyone eventually has access to. This way people actually see that you're dedicated to that champion, and you won't have two dozen level 7 champions by the end of the season.
Rossendale1 votesIt's good that you need S grades to get the higher masteries, this was it awards people who are actually "masters" at their champions instead of anyone who spammed the champ long enough regardless of performance.
JayHog19921 votesI do like it as well, in fact, I stopped playing in the Rift because it was so boring, not to mention that sometimes I only show up for weekend gamemodes.
Now I started playing the game and got 2 S ranks, getting level 6 Teemo. Might go for Level 7 later.
dunkeroni1 votesI just got level 6 teemo last night :3
JayHog19921 votesNeat! Kinda feels rewarding that I'm getting better mastery levels for effort and not for losing 500 games to get there.
Eventualy things will to fine.