Yes I agree that the Facebook employee could have responded better.
But you are mixing two different issues.
Facebook employee saying "go away" does not automatically result in a warrant for you to go ahead and exploit the bug you found.
If you do that, you no longer meet the definition of a whitehat researcher.
That kind of person is not the type that Facebook wants to reward because Facebook is not competing against the black market prices.
It is simply rewarding those honest reporters who would report the bug even if they were 100% sure that Facebook is not going to pay anything and would not exploit it or sell it even if the Facebook employee said "screw you" or if the black market bids were 6 digit figures.
But you are mixing two different issues.
Facebook employee saying "go away" does not automatically result in a warrant for you to go ahead and exploit the bug you found.
If you do that, you no longer meet the definition of a whitehat researcher.
That kind of person is not the type that Facebook wants to reward because Facebook is not competing against the black market prices.
It is simply rewarding those honest reporters who would report the bug even if they were 100% sure that Facebook is not going to pay anything and would not exploit it or sell it even if the Facebook employee said "screw you" or if the black market bids were 6 digit figures.