nettle, what I'm getting at is that I think it's not that 'do what you love' is a myth, it's that people don't use the phrase in the same way.
Choosing something you love or enjoy without looking at the practicalities is silly.
But lots of people will recommend 'do what you love' or 'choose a career you'll enjoy' and won't in the least mean 'ignore other considerations.
Yet it becomes a finger-wagging exercise, especially (IME) for Arts Graduates who're women. I've never heard anyone tell my little brother, who studied history, that he must have chosen it because he loved it and wasn't that silly? OTOH the number of people who queue up to tell me smugly I should have chosen a more 'practical' degree and not one I 'loved' is remarkable.
I find it really odd. My DP's a scientist and for some reason, because STEM are less female-dominated, no one ever assumes she chose it out of enjoyment or love, but only out of responsibility.
Not a good stereotype to perpetuate.