Every team has good signings and bad.
Every GM has a guy they overpaid thinking he had great potential.
During the Bulls' first 30 or so years they didn't have too many of those bad contracts. However, after 1998 there were almost too many to choose from.
General manager Jerry Krause did a masterful job putting the right pieces around Michael Jordan and winning three straight championships. Then he arguably did an even better job rebuilding it and winning another three titles.
However, after the NBA lockout ended Krause and the Bulls made a lot of bad choices. Far too much money was invested on guys based on potential or had injury concerns and these are some of the worst.