Heather
From what I can see here Sam and Dean have friends, people who care for them. And these people, with the best of intentions will vow to stand with them, fight for them. Not all of them will be strong enough to do it. And it may well kill them. Which, to be frank, will damage the Winchester brothers.
Please understand that I have their best interests at heart, both because they are warriors and because, honestly, they deserve it. They don't deserve the pain of losing the people they love because they got into fights they couldn't handle.