The joy/energy and human element being reduced. Or sometimes it's profit greed. Or it could just be due to economic conditions at the time. There are lots of ways for organizations to fall. Pick your poison.

The people who cared leave and are replaced by people who just want a job.

It's just economics. VCs dump large amounts of money into early-stage platforms with the express purpose of exploiting it later. This is an inevitable part of the lifecycle of high capital, low margin industries with strong network effects.

This is not VCs being evil and corrupting a pristine engineer- or hacker-defined concept of true value. The VCs are all following the rules and are trying to make money off of risky investments (it's "venture" capital, after all). But the incentive structure just forces the market into either an oligopoly of largely extractive services (or into everything being free: that's why open source is also a stable point for software).

My hope is that in time, basic software services, like for communication, socialising, community hosting, and so on, will eventually become seen as core social infrastructure. I don't really think this can happen via existing institutions, even open source, because the fixed costs of making software are really high. You really need _tax_ to support this. But it's very difficult to do because the internet cuts across borders.

Usually money.

Bureaucracy is a major one, as it tends to dissipate more and more resources to sustain its own infrastructure, neglecting the core mission (J. Pournelle's Law).

"You can divide our industry into two kinds of people: those who want to go work for a company to make it successful, and those who want to go work for a successful company." -- Jamie Zawinski

The brokenness of man? Sin?

Entropy. Game theory.

The investors.