What has gone wrong with our world that making a 6 billion dollar a year profit is considered a problem?Because it is a problem.
Firstly, it's a problem because stock prices are a measure of predicted future value. The profit today is mostly irrelevant. In order to make a profit on shares the business has to be in a position to do better in the future. If it doesn't then people won't believe it'll do better even farther in to the future, so they won't bid more for the shares than they're worth today. That means investors can't make a profit. If you bought Netflix shares in the past you'll lose money. That's a problem.
Secondly, and in my opinion more importantly, Netflix (and every other tech unicorn) use their shares as a hiring incentive. If the shares are going the wrong way then good hires will refuse offers and go elsewhere. A big chunk of renumeration in tech is predicated on people getting stock instead of cash because that's worth more to the individual and cheaper for the business. If that fails then the business has to start dipping in to that $6bn profit to replace people who leave, or to acquire businesses, or just to maintain the status quo.
It isn't hard to imagine a scenario where a $6bn profit turns into a loss within a decade or less. The driving force behind people saying Netflix has a problem is that they're predicting that the future of the company isn't good.
I mean, they might be wrong and Netflix might be fine, and ultimately even if things go badly Netflix is never going to "fail" because it'll get bought long before that happens, but if you hold Netflix stock it's entirely reasonable to be worried despite the healthy profit they make.