I guess it also depends on what that 'taste' or 'flavour' preference is based on. Is it based on that person's previous experiences (I keep reading this all sex and no plot and it's just so repetitive, therefore I think *any* plot-based story will be better than this, or vice versa...) or just their personal opinions?

If it's based on a particular view of the characters, then that's another matter, imo. I wouldn't express it as 'that story sucks' but if it's a case of "I think that's a bad story because NS would never be on the bottom" or something similar, that's their purview. Of course, they'd be wrong, but it's *their* wrongness! ;)