Actually subjective definitions are not antithetical to proper communication. Anarchy of language works. It is when people use force to manipulate language, when people deceive, that communication breaks down. It is like the subjective theory of value, which when understood and respected, leads to regular prices and economic prosperity and equality. When it is misunderstood and when power to control other people's definitions of value is fought over, dysfunction ensues. Same with the fight for authority over language.