Splintering of forums is not unusual and using the same name also occurs. I am Greenpen where ever I post. But I get a feeling of duplicity here with established and seemingly important members (people who contribute a lot) of this forum apparently taking a very different line elsewhere.
Having said that, most people here are only known through their FT contributions and can spin whatever personality they wish. And this happens a lot on internet chat rooms. I have no involvement here or on PTS, where I also post, but in the past did have background knowledge of people posting on a forum and many a virtual personality existed. (My son tells me whole computer game universes exist where being unreal is part of your life and actually costs you money, but that sort of stuff has passed me by!)