You can't genocide communists. Communists aren't a nationality, ethnicity, race or religious group
And the reason communists (or more broadly, political groups) aren't included?
The USSR opposed it.
Source.
I can't believe Mana would go against Comrade Stalin's position like that? I'm afraid she is actually a bourgeoise swine paying lipservice to the tenets of communism while engaging in bourgeoise, counterrevolutionary activities.