I wouldn't feel guilty at all but on the other hand I would never assume that it has really been what I'd written that has stopped this thread. That is a little bit too presumptuous, in my mind. I don't think that with my posts I could bring anyone to write in or stay away from a thread.
Why do you ask? Did it happen to you that you've stopped a thread that had been running for a long time? Or is it more a general debate?