I suppose that if you are a centrist then everything else out there does feel very 'other'. Although Vince Cable has a point. We do have a left-leaning centrist party, or should have. It's like everyone has forgotten that the Lib Dems exist. Although given their recent cock ups it may well be that people remember but don't give a toss.
I used to be a Green activist back in the days when they said that they were neither a party of the left nor the right, but took the approach that every decision needed to be made based on its merits and the benefits to the people. Back then because of the green mantra of 'think global, act local' they were generally anti further integration in Europe and were firmly against joining the Euro. Then Caroline Lucas declared them to be 'a party of the left' and that distinction went. I still vote Green but I also feel that means I vote left and I don't want to be a part of the 'them and us' thing.
But then that's surely, as you note, true of any centrist party. The point is that you cannot really have a party that isn't in some sense saying that you are morally superior and the 'others' are wrong. To argue as McColm's piece does that you can somehow just form a non judgemental party, unlike those judgemental people are at fault, is to expose that tolerance is never a clean thing.
The issue, I suspect , for the idea of the Lib Dems, in addition to their mentioned recent cock ups, and the garnishment of their time in govt, is that for members of other parties to join, it will be portrayed and seen as a betrayal. A new party has the benefit of being, as the newly sexagenarian Madonna sang, 'bright, shiny and new'. It's therefore not a betrayal but a new advance.
