Half of the top 10 players are currently jungle mains
1 - sorry my bad xd (who I assume is 100T Levi) 2 - Tarzaned 4 - Inori 5 - Spica1 10 - blaberfish2
there are 2 mids and tops. They are (respectively)
6 - CptShrimps 9 - FOX Damonte
3 - thtr 7 - play for KDA
and one Sivir/support main at rank 8.
The first dedicated ADC main is at rank 12.
Honestly the jungle role needs a legitimate nerf. Not one of those nerfs that just makes the camps give less gold and exp, one that keeps them in the jungle for longer so they aren't continually pressuring the map. By having the camps be so flimsy and useless we have funnel strats in LCS (have the ADC alternate farming the jungle and a lane) and in solo queue we're just bombarded with carry junglers who insist they need to take your waves to carry and will punish their team if they don't feel they have the full force of the team babying them.
Alternately we could make Smite not such a ubiquitous Summoner Spell that essentially determines whether or not your team has a reasonable chance of winning the game (if your jungler is worse than theirs, the impact is felt significantly harder than in any other role). There's a very good chance that's the reason the difference between the highest rated jungle main and the highest rated of any other role is almost 300 LP, and over 400 LP between the highest rated jungler and highest rated ADC main.
It's made LCS boring and the junglers I play with almost intolerably toxic.