The most rational response to poorly written laws is collective action against government that wrote them.
But that would require terminally online frogs acting in their collective interests, not isolating at home hoping the heat never reaches them.
Is everyone blocking them not collective action?
The copy on the linked "UK geoblocking" page doesn't contradict that, though.
The authors say, basically, that there's a risk of prosecution in the UK that would financially devastate anyone that works on the project, and that the act of determining how to comply with UK laws is itself an extremely resource-intensive legal task that they can't or won't do. In other words, they're geoblocking the UK not out of activism but out of pragmatic self-preservation.
That's not in any way mutually exclusive with collective action.
...also, couldn't deciding to geoblock the UK be a form of collective action? If that's what you originally meant, I sincerely apologize for reading it backwards.