I am not bothered by the sociodemographic data. I have worked in Market Research so understand why it is there. I never fill in the section asking for help or any identification features, so I know my entry is entirely anonymous.
I also know that the descriptions and classifications are based on standard definitions but I am getting increasingly irritated by the way they are defined entirely in terms of being an employee in a company. None of the upper definitions make any allowance for the self-employed, especially the highly skilled professionals, for example barristers, or as in DH's case Chartered Engineers with specialist skills, who work as consultants on major projects.
More and more people fall into this bracket of highly skilled, very well paid, experts, who have no interest in climbing the corporate ladder, instead make careers based on their highly tecnical skills