You're right, good taste is subjective and strictly relates to the individual expressing it. Used in the same context as Steemit quality content I think there is a line that can be drawn, from a majority point of view, to what is quality/non-quality without too much expertise behind the curtain :)
Upvote herding will happen on quality content. Again quality can be considered subjective, as you've pointed out above, but the majority of whales/users will pretty much have it in the same scope I think (content informative level, originality, catchy titles, good language control, formatting, visuals etc.).

PS. I always appreciate feedback @fishborne, never see it as aggressive unless..you know, it's aggressive (is aggressiveness subjective too? hahah).