>   I do not think they go around boasting about how bad their
 > grammar is, do they?

well, to be honest, yes some do. they say that grammar
and spelling don't matter.

 > Unlike the attitude of the chattering classes
 > to their unwillingness to understand science or mathematics.

michel said: the starting point of scientific papers (sic) is a set of
   equations

i said: i very seldom if ever use mathematical formulae in papers
 that i write

you said: the chattering classes are unwilling to understand science
  and maths

Its not clear to me how the third one is arrived at.

Sebastian