What's missing from this discussion of Smart is that his efficiency isn't as bad as it looks.
Here's the ugly stats (career):
FG%: .357
3p%: .296
These are dreadful numbers. For comparison, Evan Turner's career numbers (Turner is not a very efficient player himself):
FG% .432
3p%: .305
However, these numbers badly overstate the difference in these players' efficiency.
Smart career TS%: .476
Turner career TS%: .489
This difference is due to (1) free throws:
Smart FTr .291, FT% .720
Turner FTr .218, FT% .777
And most importantly to 3 point attempts:
Smart 3pr .510, 3p% .296
Turner 3pr .130, 3p% .305.
Even though Smart shoots a way lower percentage from the field than Turner does, nonetheless he ends up with similar efficiency as Turner because
(1) a 30% 3 is just as good as a 45% 2 (Turner 2p%: .451), and
(2) the most efficient type of possession for both players is free throws, and Smart excels at drawing fouls.
All in all, Smart's efficiency is bad, but it is not as bad as it looks. He needs to improve, but as fans we shouldn't be wringing our hands and proclaiming him a bust.