I suspect I'm misreading your comment. You say "they run near empty flights often", which is not true based on current load factor data, at least in the US[1]; it's as high as ever.
But you also say "it's a sellers market" which would imply high demand where they can afford to lose a few passengers (which would be true based on basic economics). So I suspect this is what you intended to say, unless I'm really misunderstanding something.