I think a little correction is in order in that I did say "very few" I didn't say "all". I will concede you may well be one of the very few supporters who have told the SPGB where they think we are going wrong. I assume this has been through the letters pages of the
Socialist Standard available here:
http://www.worldsocialism.org/spgb/index.html .
If not you make quite a good case above which will suffice for discussion. We argue that we are the creation of the political consciousness of the working class and as such have no reason to abnegate, or relinquish, the essential purpose of gaining working class support and capturing political power as a result.
Yes we could exist purely as propaganda organisation, or even as an educational organisation. This issue is still being discussed amongst the members. But so far all it as illustrated is whether or not this would serve any useful purpose is debatable and a moot point.
In fact the founders of the SPGB in 1904 took in my estimation the wisest course and choose to combine all three e.g. the political with the propaganda, and the propaganda with the educational. This is based on the sound conclusion that the class struggle encompasses all three and is essential to our participation in the political process for self-emancipation and the establishment of socialism/ communism.