Because they murder without discrimination, it doesn't matter if the werewolves are dangerious or not they kill them simply because they exist. They do so for pleasure not out of some duty to protecting the peoples of skyrim.
Well, Werewolves are dangerous. They kill the innocent as well.
I wish all the quests had more options and outcomes. Joining the Silverhand would have been a welcomed addition. They could have been a unique faction, in lieu of copying the Bandit actors.
I haven't heard of the dawnguard nailing vampires to walls likw the silverhand does to werewolves. If you approach the dawnguard as a vampire but without siding with the Harkon they simply tell you to get cured, there really isn't evidence they hunt vampires that don't deserve it.
No evidence? The Dawnguard has a torture chamber, for crying out loud. With Vampire skulls lining the walls. It's rather evident they do some pretty bad things to blood svckers.
Them not attacking the PC is bad scripting. Not really from getting the disease after joining, as that can easily happen while combating Vampires all the time. But to even be able to enter originally as a Vampire makes no since at all.