Rangers already have a buttload of granted feats, yes, but most of that is tied into making it somewhat realistic to have a char that has passable ranged and TWF melee ability, with a focus in one (AA or Tempest) with a backup in the other.
Its more important, perhaps, for a Tempest that wants a decent backup bow, than an AA who might stay with bow even in melee range - but the Tempest is going to need to devote more feats to melee than the AA will to ranged combat feats.
So even with all the granted feats, with no bonus feat slots, most Rangers arent going to give up a feat slot for Quick Draw, whose primary benefit is the instant weapon switch, not the increased thrown weapon speed. It does make sense, though, to have that in the Ranger skillset, and might make it slightly more desirable to actually have a weapon-switching playstyle, which is more onerous than its often worth with the 1s weapon switch time.