This questions seems to come up at least once a year and there is still a lot of erroneous information passed off as fact.
Let me just clear up a few things.
#1- Pierce was not outplayed by Cutino Mobley. They never even guarded each other. Pierce played small forward his entire college career. The guy that got out played by Mobley did have a short stint with the C's however, remember Billy Thomas? True, Pierce couldn't hit a single outside shot in that game but he still finished 9 of 19 with 23 points. Thomas was 2 of 15. I've never heard any NBA scout point to that game as a negative.
#2- The poor workouts was a rumor started by Denver after they immediately caught tons of flack for their choice of LaFrentz from their fans and hometown media. Pierce and his agent adamantly denied those rumors and even the other GM's he tried out for came to his defense on this issue saying he had great workouts.
#3- The only team Pierce's agent said he would not play for was Toronto. He made a choice that he would rather play near friends and family in his birth town of Oakland. No one even considered he could go lower than that. The problem comes when Denver picked size in LaFrentz, the Warriors picked size in Jamison (in a trade with Toronto for Carter), the Mav's picked size in Nowitzki, the Bucks picked size in Traylor (also in a trade) and the 76ers held to their promise to Hughes. Sacramento's choice was just odd, although his ESPN highlights did bring a lot of fan buzz. A lot of dominos falling against Paul, only one of which he had anything to do with.
#4- Carter and Jamison were both highly thought of, both being consensus all Americans, as were both Pierce and LaFrentz. As has already been mentioned Hughes was also well thought of having been a freshman force at St Louis playing basically as a one man team.