Bonus Damage From Blood Pact Feat SW

So when I started playing I took advice frm anyone that would offer it. Good, bad, awful. Took it all. I was always told that Blood Pact of Cania was broken and any points after 2 didn't actually add DPS to your SW. Has anyone tested this? Why is it that most builds only have 2 in a stat that is very clearly a great increase in damage. But no one uses it. Are we all sheep or is it actually bugged?