Up to every individual whether they change their name on marriage or not - where have I said otherwise?
But it's also up to the individual whether they double barrel or not. What's the difference?
I speak merely from the experience of living for well over 30 years with a double-barrelled surname, and over a decade without one... which makes me quite well qualified on the subject.
And speaking from experience as a woman who chose not to change her name on marriage, literally all the arguments you have made against double barrelling could also be made against keeping your name when you marry. People get your name wrong - either carelessly because they assume you will have taken your husband's name and can't be arsed to check, or deliberately because they think you should have changed your name like everybody else does and who do you think you are, making some sort of feminist standpoint?
When I was trying to decide whether to change my name or not I read an article listing the pros and cons and explaining how each option worked. The author explained that if you change your name on marriage you have to produce your marriage certificate as proof of your entitlement to use your married name and then you can change the name on your passport and driving licence. It explained that if you want to have a passport in your married name to travel on your honeymoon you can get one in advance but it won't be valid until the date of your marriage and in the meantime you won't have a valid passport. Alternatively you can keep your existing passport until it expires but then you need to remember to book any travel tickets in your maiden name. Obviously changing your name on your passport and driving licence is an administrative burden and costs you money. But when you've done that you can contact your bank, utilities providers and everyone you have any kind of account with and provide evidence of your name change so you can be referred to by your married name.
In the part which describes not changing your name, it says you don't need to do anything at all. You get married and apart from that everything stays the same.
The article nonetheless concluded by saying that the simplest and easiest thing to do is to change your name to your husband's name on marriage because that is what most people do.
When I read the article I thought the conclusion was fucking ridiculous. You've literally just described all these tedious things you need to do if you change your name and said that you don't need to do anything at all if you don't change your name. How can you possibly then conclude that the easiest thing to do is change your name?
But having got married and not changed my name, I now often think it would have been simpler to change it. Half my medical records are in the wrong name because the hospital can't get their heads round the fact that I don't use my husband's surname. People send me things which don't fit in my letterbox and so I have to pick them up from the post office only they've addressed them to Mrs Hisname and I don't have any ID in that name.
If only I could just forget about all my pesky feminist principles it would indeed have been much easier to take my husband's name, and then I wouldn't have a lifetime of getting annoyed with people when they call me by the wrong name.
These are all the same arguments that you are making in favour of not double barrelling.
They're also very similar to arguments you could make about not fighting for women to have the right to vote, or for equal pay, or for abortion rights, or for marital rape to be illegal.
It's always easier to accept the status quo than to fight against it. That's not a good argument for doing it though.