> I'd argue most bugs are there because the cost of a bug is less than the cost of developer time
You make it seem more planned and reasoned out than it really is. I mean, you can make a meta-argument, that market evolution and pressures push things towards that optimal cost-benefit spot, but on the micro scale it often just happenstance.
Again, the meta-argument can be that even doing the cost-benefit analysis is not worth the cost, but it's quite handwavy.
What counts as "better" anyway? From the engineering perspective it's about efficiency, bug-freeness, elegance. From the company perspective, profits. From the manager perspective, looking good and getting promoted.
You can often game the system by rushing a subpar product out the door, downplaying and not even caring about the defects, wooing customers into buying in with clever sales tactics and marketing, then moving on before things start crumbling down. In some sense this was worth it in terms of your personal costs and benefits and all was done in the best possible way.