Goodness me. The "isolation" argument is pretty tenuous as it is IMO, but at least with that there was an attempt at relating things back to Dan directly. However, when Dan trying to reunite Blair with Chuck gets twisted like a pretzel into Dan somehow being responsible for not only the accident, but Blair's miscarriage, I think we're getting into a borderline crazy, nonsensical debate free from logic and ruled by the need for Dan to be the bad guy no matter what. Somehow I get the feeling that Dan could bring about world peace at this point and it would be used to argue that it's all part of his evil plan to isolate Blair from Serena and stand between her "epic" love with Chuck.
It's a free world and no one is required to like any character, but for heaven's sake, not everything can be twisted into Dan being responsible for all the injustices of the universe. Unless the argument is based on facts and not conjecture or a series of completely disconnected events.
I also don't understand why there seems to be an attitude that Serena/Chuck/Nate are all entitled to be Blair's only friends ever, for the rest of their lives. Things evolve, people form new bonds and new relationships. Dan and Blair is a relationship that evolved more recently, but the fact that it's new doesn't make it any less valid a friendship than Blair's relationship with her other friends. Inherent in the "Dan is isolating Blair from her friends" argument is the premise that Dan is not "really" Blair's friend and it's somehow wrong for her to rely on him. That Dan himself doesn't actually "count" as her friend. IMO when it comes to friendships, actions speak louder than a thousand verbal declarations of BFF-ness or the quantity of time people have known each other and over the past season or two, Blair's actions have said that she trusts Dan more than her "BFF" Serena. Dan has never actively sought Blair out and forced her to rely on him. Blair has been running to him over and over of her own accord. The fact that Blair is now closer to Dan than most people speaks of Blair's own choices as a grown woman, not of Dan being a manipulator.
Yeah- I have to say - I am equally bemused to find that this is all Dan's fault- Blair asked for his help and he helped her- Serena and Chuck just led the Grimaldis to Blair's hotel room and then Chuck offered to buy her out of her marriage contract- even accepting that they best of intentions- neither of them in fact helped Blair at all- and who does Blair seek our before she leaves to put things right- Dan (again)