Not disputing that there MAY be a concentration of people of doubtful sexual preferences among MPs, or, within the BBC, but, do you have any facts or statistics to actually support this supposition? ie that the incidence of "offenders" is any different to the general population, or, any other selected sub-set (say, for example, Police, NHS workers, Teachers, etc etc).
According to The Guardian, two thirds of local councillors are men. If so, that might well account for it. If you did the same research for nursing you'd probably find very few are convicted of sex offences or child abuse images, even though there are thousands more nurses than councillors.