[icebraining]

It's not, though; the developers can write the code, but they can't force people to upgrade.

[wmf]

They can withhold features that people want by refusing to code them, which is what one of the controversies is about.

[vertex-four]

But other people can code them, and people as a whole can choose what software they want to run?

[twblalock]

If some large exchanges upgrade, and some don't, the consequences are similar to those of a code fork. Suddenly the currency becomes split into two different currencies.