Why? 30sc doesn't do anything different than the 9mm dies now, with the exception of what 2more rounds.
A local outdoor store went super deep on that round. They brought in guns chambered for it and a ton of the ammo, very very few bought into it. I think many consumers do not want to get sucked in and in 6 yrs there little or no support for it from most of the manufacturers. Remember the .40 was the darling and now with the exception of CZ no new platforms have been brought to the market in years, not to mention most LEO's have ditched it as well.
Honestly that is another round in my area they practically can't give it away.
My local shops will not even take a .40 in on trade.