Hypocritical objectivism is a term I'm coining for arguments to the effect of "the thing I value must be the only objectively valuable thing because all other values are subjective". Believe it or not, I have two examples.
Many anarcho-capitalist purists argue that property rights must be an absolute overriding any other moral value because all other concepts of morality are somehow "subjective". Of course, their claimed logical derivation for it falls apart with the tiniest smidge of intellectual honesty.
I've seen a number of people do the same thing with game design. I can think of two people, Chris Wagar and mrguy888, who believe that depth and determinism are the only objective values of game design because everything else is subjective, and thus dismiss a priori any arguments that a game element is poorly designed for any other reason. (To avoid slander, Chris Wagar has not raised this argument against others to my knowledge; though he's strongly implied he believes it in the comments here.)
Of course, this demarcation is just as arbitrary as that of anyone else who uses the "your opinion" cliche, because even depth is technically person-relative since a culture or individual who finds the game mechanics intuitively pre-solved will experience less depth, and there's nothing any more relative about other game design values, like the idea that failure should not have persistent consequences. Games exist to provide enjoyment, and psychology isn't an arbitrary mess.