Yes he is not a good shooter, neither is Rajon Rondo...In my opinion they are exactly what the definition of a true point guard is (pass first, setting up teammates).
Rondo is actually quite a effective scorer, career FG shootin at 48% (24% 3PT)
Rubio FG 36% (32% 3PT)
Top teams have starting PG capable of scoring (Parker, Westbrook, Ty Lawson, Stephen Curry, D Will, D Rose) *Hence all playoff teams
Rubio is all fun to watch and all, but he needs to improve his scoring. Rubio is like a CP3 with less PPG