@wafflehead2013 I don't really see a problem that Grohk is not viable as main support. He is viable as off-support. Not every tank is playable as main-tank so why has every support to be playable as main-support. Especially with the new double-support meta.
Grohk is good in doing damage and he has good self-sustain and therefor his healing output is bad to keep him balanced. If his healing would be buffed he would be overpowered.
I also don't think we need another dps champion. There are many to choose from already. Especially now with double support meta the number of supports shouldn't be reduced.