The weight and dimensions being negligible are your opinion. I don't agree they are negligible. If they were negligible, why would people have bought it in the first place? Getting "so much more with the Compact" is also your opinion. It seems as if you already have a firm opinion of the Compact being better than the Shield, and that is OK, after all, it is your opinion, so I'm not sure what it is you want to know? The differences between the Shield and the "C" are pretty clear to me, so it really come down to personal preference, what feels good to the buyer, and what the buyer wants to pay.
The Shield is a great alternative and a reliable weapon for people that want something to carry that is manageable but effective. It's affordable and I think it's fun to shoot.