Ft/lbs of energy is not particularly important for handgun terminal ballistics if it doesn't result in a larger wound cavity through expansion and/or penetration depth.

However, .30 SC seems to do as well as plenty of 9mm rounds when it comes to penetration and expansion, making it perfectly viable as a carry round, and in a Shield Plus, you get an extra 3 rounds of .30 SC.

When it comes to concealed carry self-defense shootings, reloads almost never happen, so capacity matters. I can't tell you how many rounds you'll need in a defensive shooting; everybody's ability varies, and common threat levels vary. Maybe criminals by you tend to run solo, or maybe you live in or around Chicago, where carjackers run in crews of 4+.

I would've preferred that .30SC be a modernized, rimless .32 ACP with a little more zip to make it a better pocket pistol round than .380 ACP. However, I can see the argument that a lot of shooters consider 9mm to be the floor for terminal effectiveness, so the designers probably wanted a round that would at least match that.