The world is full of dogmatic and narrow-minded folks. For instance, in the urban sketching group, there will be those who cannot accept that people sketch outside of urban sketching too and these narrow types will want them others to adhere to the so-called manifesto.
People don different hats at different situations to draw and paint. People have their own reasons for drawing and painting. If you were to be different from them, you will be labelled as 'extreme'.
You would think that an art community would be full of open-minded and liberal types. However, I find it full of conservatives and the narrow-minded.