This was not a typical case of throwing a match. The banned competitors did not decide to lose in order to benefit outside the competition, like the 1919 Chicago "Black Sox," who threw the World Series to claim a share of the money from winning bets. These badminton teams tried to lose to increase their chances of winning the competition itself. It was good strategy, not corruption, though it was not in the spirit of the Olympics. The players were placed, by the structural rules of the tournament, into a very difficult decision--try to win the match and sabotage their chances of medaling, or deliberately lose and violate the Code of Conduct.
It is the fault of the structure of the tournament that they were forced to make such a decision. In previous Olympics, a single elimination system was used, such that if a team lost a match they were out of contention. If these rules had still been in place there would have been no incentive to lose. A pool system was established for London to ensure that all competing countries played more than one match, which led to the problem.
Efforts to create greater inclusiveness already contributed to injustice and a diminished quality of competition in the women's all-around gymnastics event. Allowing countries to compete as much as possible in the Olympics is an admirable goal, but it should be a secondary concern to ensuring that all events are credible and legitimate. A structure that commonly causes scenarios in which it is in the athletes' best interests to lose is not legitimate, and an event in which top competitors have been disqualified for trying their hardest to win is not credible.
The preliminary round should be eliminated in a sport where seedings are so crucial to ultimate success. One option is for badminton to go back to the previous system of single elimination. If the sport wants to include more countries in the tournament for more than one match, there are other possible structures that would never incentivize losing. One alternative is a double elimination tournament with a winner's and loser's bracket.
Either way, badminton and other sports with similar tournament structures need to make a change.