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.

"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

Usually money.