It is a very extreme position to say that there is literally nothing which can be generalised about people's experiences, and so one person's heroin main-lining hobby is as good as another's model railway collection so long as they both profess an equal belief in their respective enjoyment.
There must be something more than this that we can say, since we have the distilled thoughts of millennia of some of the most capable humans thinking about these questions (what makes a good life) and lots of case histories of how people's lives have gone.
This is different from judging someone's moral worth or probity or what have you, and I think it is harmful to gloss over the distinction because it creates a kind of skeptical collapse.
This might be what the prior comment means to indicate by getting a life - that we should each individually research this question and not presume we've got a good answer already. If it is what they meant, I agree that their phrasing was unskillful.