I generally agree that this process doesn't sound all that terrible for code that controls a large, live manufacturing line. Try changing the code that runs a pacemaker - you'll learn all sorts of things about process.
This line however is the road to hell:
"if the company wants to spend $50,000 to change 1 line of code, and it's not going under, then that's obviously the right decision"
Just because a company is successful does not mean it does everything right and does not contain the seed of its own destruction.
Really, I think the problem with this scenario is not that the company wanted to "spend $50,000 to change 1 line of code." The problem is that management wanted to spend $500 to change one line of code, the dev team spun up to spend $50,000, ended up spending maybe $5,000 before management told them "no really, we don't care about what you think, give us the $500 fix."
This line however is the road to hell:
"if the company wants to spend $50,000 to change 1 line of code, and it's not going under, then that's obviously the right decision"
Just because a company is successful does not mean it does everything right and does not contain the seed of its own destruction.