The reason to make it possible for all classes to be able to support is wvw queue's . Don't be thick lol .If your party need's you to swap to support or dps , you just change build/gear.
Also I am a fairly new wvw player , i have played in boonballs and against them . Boonballs seem more effective by far , but also boring as kitten , who is the idiot that thought this garbage up?