Regarding the comments about Portlandm it is interesting to note why they selected the way they did in the two scenarios you highlighted.

Jordan was coming out as a Junior, having averaged about 18 pts. per game at North Carolina.  Portland had a 2 guard in Clyde Drexler that they had just drafted.  Adding Jordan to that mix would have been very questionable.  Furthemore, it is clear that the NBA is a big man's league, and Sam Bowie was quite promising coming out of college.

It's a similar situation with the Durant, too.  They had just drafted Roy, and the chance to stock the frontline with Aldridge already in place made a lot of sense.  Adding Durant may have created a situation where too many players needed the ball.

I not defending their picks ... it's just interesting to look a little deeper as to why the choices are made at any given time.