Disapproval, not discrimination
It is far from "fact" that "sexuality is not something you choose... it is part of your make-up, as natural to you as your skin colour". It is still very much an open question whether that is the case.
Brian Souter was pretty clear about where he was coming from in the Scottish referendum on Section 28. You may well question the validity of the result but it's a bit rich to go on about it being undemocratic when the Scottish politicians refused point blank to allow the people of Scotland to have any say in the matter.
Prejudice is not necessarily a bad thing. We are prejudiced against neo-Nazis and paedophilia, are we not? What about racists? What about homophobes?
Logically speaking, you cannot bleat on about the need to eradicate all "prejudice" and then express prejudice yourself about people of whom you disapprove.
Don't confuse disapproval with intolerance. As the great John Stuart Mill put it (to paraphrase), just because we are prepared to tolerate certain forms of behaviour doesn't meanwe should not have the right to disapprove of them.
Many countries maintain systems which offer economic incentives for married heterosexual couples with children. Of course, such incentives discriminate against everyone who does not fit into that category. When a single person (gay, lesbian or hetero) does not qualify for the same tax breaks as a married heterosexual it is not an infringement of their "human rights". There is no human right to a tax break. Nor is it a human right to insist that taxpayers' money be used to "promote" alternative lifestyles (sexual, religious or whatever). Thus Section 28 is not about human rights. It's not about saying to heterosexuals that their homosexual peers are "inferior" either. It's about society simply choosing to have an opinion about the relative merits of a heterosexual versus a homosexual lifestyle.
In any event, your correspondent John Cattermole (TES, August 18) can tell his primary school colleagues to sleep easy. Section 28 does not ban anybody from talking about gay issues.