MakeMathsFun
Your long post completely misses the point.
I am well aware that You are indeed within your rights to use any title you like (as long as you are not being deceptive for profit, eg illegal use of Dr, Sir, Dame, Prof, etc.)
I think the point that most people are missing is that the only reason businesses collect this particular information is so they know how to address you appropriately to your preference
Er no, I don't think anyone has missed that point.
The point, which has soared over your head, is why on earth does there have to be separate titles to show whether a woman is married or not whereas all that is required for a man is something to show he is (a) male and (b) over 18.
For many people (but not all), marital status can be a sensitive subject. So people need the choice of Mr, Mrs, Miss, Ms, Madam or other to cover all people's preferences
This makes no sense at all. "Mr" discloses nothing about a man's marital status. There's no reason why it should- the airline is transporting him A to B, not thinking of getting hitched to him. ("Madam" isn't even a title).
Why do you think women should disclose whether they are married or single but men don't need to?