One guy who was a top level MKX player does well in online play, while every offline tournament features 0 Scorpions. Solid character and viable for sure...
He is more than viable. An honest character with decent dirt of his own. He isn't used as much because there are many characters have way more dirt.
Just because characters aren't used in top 16 doesn't mean they are bad.
If that was true then half of the cast would be considered unviable.
This has been displayed by several mid to low tier characters placing top 16 to top 8 like kotals multiple top 16's or recently Frost, Jade, Kitana and others.
I think he is a solid character, fundamentally he can play the strike throw meta and even has decent staggers, plus frames and cancels even decent KB's as well as having a decent mid, and good footsie tools.
He isn't top tier but I think he is fine