It looks like the prevalence is low and it can easily be blocked with blocking the scripts in question.
Nevertheless, what needs to happen is that all major browser makers come together and simply create a set of standard API values that do not harm daily browsing and make it possible for users to blend in with the masses, if they opt-in to activate
It would be sufficient to create a couple of uniform user agents, list of fonts, list of plugins, canvas hash, platform and webgl data to bring the uniqueness down.