If you "swore you'd never work in a low-margin business again" then you will either work for a niche company for as long as it is in a niche, or for a monopolist.

Low-margin is another way of saying, "competitive." I've consulted for companies from 1 man to Fortune 100, and mostly in the €10s of billion/yr range.

Everyone is looking at costs. Cash flow is king. Your example may be extreme, and the CFO sounds like a micro-manager, but I've seen small, high margin companies that went out of business in a matter of months when the market got tight based on the idea that money will always be there.

One real-world example: I knew a firm that sent nearly everything by $50/piece courier rather than $2/piece USPS for years. This was the equivalent of multiple employee's yearly salaries basically lit on fire. When things got tight, the company had to fire people who might have been able to turn the company around. The company didn't make it. Just because they wasted money on postage? No, but that attitude was a big part of the problem.