Well I think it's because this idea of no attachments is alien to most humans. That whole philosophy itself seems confusing and contradictory. You're encouraged to love but you cannot 'have' love?? WTF? And we do tend to view it as a causal factor in Anakin's turn to the darkside. If Anakin had simply been allowed to free his mother from slavery as he wanted or to even go check on her at some point, if he had been allowed to love someone openly and not have to keep it a secret - he would have had so fewer reasons to resent the Jedi. Given how we identify with his need to keep people he loves safe - 'attachments' as the Jedi call it - that's just basic humanity to us - we the audience blame the Jedi for his turn at least as much as any other reason and so that gives us the impression that the films are presenting the Jedi teachings as flawed since they contributed in no small part to everything that follows.
But yes, your Lucas quotes do suggest more that he is advocating the Jedi philosophy and, I guess, putting all the responsibility on Anakin. And yet all I can think is how the hell this doesn't happen with every second or third student. It IS a flawed philosophy. I find it so silly it's a big reason I've never liked the PT