Because of a few things, (1) the waivers are revocable, so teams can just pull the player back if the Nationals claimed their player and an equitable deal could not be reached; (2) there is a waiver claim fee and regardless of what the LAC crew might say, it's silly to just throw money away at claims they have no possibility of making a deal for; and (3) teams have long memories, if the Nationals consistently claimed every player on waivers, they are damaging future negotiations with teams by screwing up their chance of dealing guys to other teams.