A simpler yet effective design (may it be initial or rework) comes at a much lower cost than a flawed one, which inevitably aggregates irrelevant complexities.
Who decides this? This is not a trivial question.
The F-35 fighter is a good example. Trades many disadvantages (not fast, not good in dog-fighting, tremendous long maintenance time, low payload etc.) for one advantage. The F-35 may or may not be invisible to an able opponent. But this decision is a tremendous difficult one. Based on your argument, it would be better to stick with a simple design. This was worked for the Soviet Union in WW2 (don't build the best tank, build a decent one, build many).
You may like this story: https://en.wikipedia.org/wiki/Superiority_(short_story)
I'm not comparing simple vs. complex but rather sound vs. flawed, although often sound = simpler than flawed.
The 737 here is yet another example of this : - the MAX design is flawed : faulty risk assessment of MCAS, seemingly unstable airframe in some configurations - a likely sound design could be : airframe rework, thorough risk assessment, extra pilot training...
While the flawed design came at a lower initial cost, it will now overrun the cost of a likely sound one (further rework + retrofit + sales/reputation damage + legal), including the cost of a probable longer design phase in the latter.
(I concede that legal/sales costs are not directly technical debt costs).
Are you an engineer? Your argument sounds naive. Or to give a counter example: In the Soviet Union there were likely more accidents (normalized) compared to the west. Yet, they did not focus on maximizing profits.