I'd simplify this post down to this: companies optimize the trade-off between time, cost, and quality by sacrificing quality.

It's not that the goal is to write low quality code, it's that big businesses understand the sales cycle and how to maximize profits. If they over spend on employees, that cuts into their profits or causes the product to be too expensive. And if they spend the time to write quality code rather than developing features, they lose sales. Customers don't buy quality, they buy features at a price, and quality issues (like bugs) get thrown over the wall to downstream support staff.

As much as I dislike this, knowing how unstable it makes the overall software ecosystem, companies aren't wrong for making these decisions. The companies that choose differently don't become big businesses, they either stay small, get acquired, or go out of business.