Thresh is the perfect example of player reward and champion unhealthiness all at once
So, we all know that while alot of supports step into a few areas they are primarily set into a role.
We have your supports that are all about healing with the goal of out sustaining the enemy 
These are countered by bursty all in/pick supports who catch out a champion and lock them down with CC

These are countered by peel supports who while they can use their skills to initiate are much better using them for defense
(I know, Tahm deals damage, i get it) 

These are countered by poke supports, who just wittle one or both of the enemies down and shove them out of lane (though these are also countered by all in/pick supports

Which are countered by healing supports and the cycle continues
Then there's Thresh, who's apperance from day 1 killed support champion variety.
For one he has the all in power, a stun which he can gap close, a knock-up, a 99% slow so he can deal with heal supports and poke supports Next he has alot of peel, again his E his ult and his lantern, so that counters All in and to a lesser extent pick supports Next his E passive means his basic attacks HURT so he can poke down protect supports.
The only thing he lacks is healing which means only poke supports have the advan-wait he also has all in power
Since Thresh now has fingers in 3 of the 4 support pies no support can outright "counter" him like other supports can, this just flat out makes him the most unhealthy support hell the most unhealthy champion in the game
And yet he gives people playing him the most satisfaction.
Lets look at Blitzcrank, if you land a hook then your rewarded at that, but now your just waiting there for it to come of cooldown, Thresh however can be rewarded landing a hook, or saving a carry, or preventing a 4 man gank from chasing which to many players is great.
So I have to wonder a few things
for one is Riot planning on giving the other supports a helping hand or Thresh a light tap to stop him from preventing support diversity
for two Does riot consider Thresh a good champion? like in terms of healthiness to the support role and for player reward?