While I doubt the tacticool folks would be interested in a shield sized gun to start with... what are the handicaps here? Serious question; I have a 1st gen Shield 9 and it does everything a full size gun does but ammo capacity.
Hell, when I first got my M&P9 longslide for steel challenge and I couldn't hit squat beyond the 7 yard plates, I ran the same course with the Shield to make sure it wasn't me. It wasn't - other than not having 10 on board the Shield ran steel challenge stages just fine. The longslide needed a trip back to S&W and an Apex barrel to get there.
#1 Reputation. It will never be as desirable or popular as some other brands that are in or very close to the same price range. If you are the kinda guy who keeps every gun you ever bought, no biggy, but if you like to trade and sell every few yrs the S&W Shield/M&P line has never held value like some others. Hell, I've always bought low and sold high, made $1000's. But that's not for everyone.
#2 Capacity. Some love a 1911 thin grip and are great with accepting 7-8 rounds in trade off. In a modern gun, I wouldn't take this to a gun fight but if it's for someone who typically wouldn't be able to hand a 12-15-22 round modern poly gun, this does it. (Personally if this was intended for me and I wanted a S&W, I would get the new Shield Plus that has that new fat magazine or wait to see if they make an even better EZ version).
#3 Quality/reliability. They don't get torture tested and win govt/LE contracts so we don't know how reliable they really are. I read great things about these (enough to get my wife one) but it's always made me happy when I get the same thing some agency uses and can rest assured it's been vetted. The1x I took it out, we had 1 FTF maybe 2 but definitely 1.
#4 The grip safety is ugly (larger on the performance models) and also sticks into some people's hands. Not mine but some wrote about it complaining and file them down.
#5 Training, if you draw and push out you'll definitely forget to the knock the safety down if your getting shot at. Unless you're a 1911 guy (this fits the 1911 fine motor skill set perfectly), you'll need to invest in a case of ammo and re-train your brain if it's your CCW.
#6 This is very personal, accuracy. My sights were way off. I shot tiny groups w/P365, G43 and any Sig P series. Tiny! But I shot like **** with this Shield EZ. Note, I only shot it 1x.