And to move is to risk a quick death. I wished existing brands stopped innovating so much. That's e.g. what got Pebble killed.

Doubly so when a brand reaches infrastructure level - like Github, or arguably Dropbox. Just don't screw with the product that's working well. Not breaking things isn't expensive.

That's not as big an issue when there are network effects -- look at Craigslist. Plus, what killer feature is bitbucket going to add at this point to make everyone want to switch? They're practically the same product. All the major innovation happened years ago.