One, that a dumbed-down associate's degree from a taxpayer-subsidised community college probably isn't going to make the recipients of the dumbed-down high school diploma any more ready to start attending the dumbed-down freshman year at their overpriced, grade-inflated university, or any more ready to enter the dumbed-down workforce. Just as taxpayer-subsidised public schools do not, generally speaking, attract the best teachers, I can't imagine that a taxpayer-funded community college would be featuring the cream of the professorial crop.
Two, that in this life, you not only get what you pay for, you also VALUE what you pay for. Conversely, you don't value what you don't pay for. The state of subsidised housing projects should give us some idea of this.
Finally three, that if the President wants to throw a few trillion dollars at a program which will do nothing more than raise the general level of American mediocrity a few degrees, why not use it to give scholarships to the really exceptional students who might not be able to attend first-class universities?