> So why would you expect businesses to behave in a way other than maximizing ROI?

If I had invested in a company, I would prefer them to maximize my return over a span of decades, not over the next quarter by inevitably undercutting their long-term performance. For some reason, the market currently favors short-term gains in a way that inevitably compromises long-term results.

Because maximizing ROI hurts their business long term? Only CEO's on a short stint of 2-3 years, with compensation based on stock market valuations go for maximizing ROI...

Reducing R&D investment is maximizing ROI in a way...

Plenty of people, myself included, don't pick investments based solely on what has the highest ROI. Some even pick investments based in part on whether or not they agree with the way the company is run.

This is true but all the same is true for privately owned (eg VC backed) companies; maximising return (within whatever risk parameters shareholders are happy to accept) leaves plenty of room for disagreement about what the right way to do that is.

But often a change in ownership can also mean a change in risk tolerance, investment horizon and potentially in management incentives or management team. Some of these changes could align negatively with some customer interests and therefore caution from customers (especially those who worry they might not be seen as future core customers) is understandable when what has changed is unclear.

An excellent teardown of modern capitalism.