Being completely indifferent to the soundness of a publicly traded company's business model is the correct choice for most ordinary people trying to invest their retirement savings, because they have no basis for thinking any other choice of how to invest will result in superior returns. This is the entire line of thinking behind all passive index-fund-based stock investing.

And in the end you have a market where nobody has any basis for thinking anything has any value, and the market ends up being a random walk.

Nah. The more irrational it gets, the more margin available to active. There's always an incentive for active investors to participate in price discovery.