The writers get to say who Blades are, not the players. We can hate them, but I don't see the point in looking for that kind of rationale to do so.
actually i got the conclusion of point 2 that was explained with point 1 AND 3. Yes wayyyyyyyyyyyyyyy back in the day the blades were dragonslayers BUT that is not even thier main focus or reason of existence. their main focus is the survival and protection of the dragonborn....then kill dragons is offtime or if one shows up BUT hey that was over a thousand years ago..
Anyone let me say again.....the blades pretty much have no idea about thier identy because of
A. The Blades are the bodyguards and advisers of the DragonBorn...their sole existence is to serve, protect, and advice ME the dragonborn, noooooottt the other way around.
B. Why is the "Blades" gonna not help or do their job with the DragonBorn when lets say he/she refuses to kill Paar...the same dragon who met and adviced Tiber Septim of going south to form his empire ans such ANDwhen pretty much EVERY emporer/dragonborn they served REFUSED the Blades to go and kill Paar BUT now that thye have found a reason for thier order to exist again they gonna throw it all away IF i choose to follow the same path?
C. How are the Blades even gonna think about giving the dragonBorn an ultimatum??
D. yes this couple of "blade" pretenders have forgotten ro never even knew what thier order stood for, ALL they seem to knwo is that WAYYYYYYY back in the day they killed dragons but careful omitted looking at what the Blades did before that AND the thousand years AFTER the dragon wars of what they did and what thier purpose was.........soooo ya either the blade members are trying to change what they were and foundation and have the dragonborn serve UNDER them or they pretty much never knew what the Blades were to begin with.