For me it's his shot. It's flat and the trajectory wavers on every release. He doesn't have a consistent release.
Players who shoot like this have up and down moments where sometimes his confidence is up and he makes more, but on the other side when the confidence wanes, the shots are mostly bricks.
Waterman just doesn't have a proper shooting form in my opinion. What is he from the FT line? 2 for 9? He's not getting robbed on his misses, they're pretty much bricks.
As for Smith, it's all about timing. On his bad misses, he's shooting too fast, trying to get the shot off before it's contested. After missing so many like that, his confidence is shaken when he has time to shoot and he continues to miss.
His best shooting this season is when he makes a few early in the game, but when the Cards are trailing and having trouble scoring, most of his shots are too fast and too deep. That's not a recipe for success unless you're name is Stef Curry.
Waterman actually impressed me more these last two games with his inside play and rebounding. I think he needs to take less perimeter shots going forward, especially now Pryor is out for the season.