It's because X is chosen (wrongfully) as the main communications channel of all kinds of important public institutions and people (police departments, city administrations, politicians, etc.).
Of course that's a real issue since the whole thing is login gated and inaccessible. But unfortunately it is the reality. So I think something like XCancel is needed.
Maybe if people didn't make services like XCancel, the impracticality of X would be more salient.