Not nearly. The limb pieces, while lacking attachment parts, are perfectly usable for humanoid MOCs. The claw and feet pieces were really cool too. I think the biggest problem with the line was the perceived low value. As you said, the parts count was rather low and I suppose most folks couldn’t justify the above-Constraction-average prices.
The only really specialised parts are the heads and torsos. The current Star Wars Constraction sets suffer from the exact same issues, and yet sell pretty well. That makes me wonder: what would Ben 10 have looked like as a CCBS theme?
EDIT: The Ben 10 torso actually has more connection points then the SW Constraction torso and the 2016 Toa torso. Plus, the sticker is removable.
<img src=“/uploads/db5640/original/3X/c/5/c53b59e02821bfa2553129defe5d4c6917921660.png” width=“300” height=“383”