If I were to rank the qualities I would want the school to impart to my DCs mindlessly following pointless and often sexist uniform rules without protest would not make the list.
Yes, but why should a school base anything on what YOU personally would put on your list of desirable qualities?
Should everyone be able to decide which rules they consider worthwhile and ignore the others? Maybe tell their child not to bother turning up for certain subjects because they are pointless? Or ignore certain behaviour rules because they don't agree with them?
A school needs rules. Quite a lot of them. They give clear boundaries to kids, many of whom badly need some boundaries. Sure, some of the rules are more important than others, but that doesn't mean it's ok to just ignore the others.
And why is it 'blindly' following rules? I'm sure that you or the school can explain to your child the reasons that schools choose to have a uniform (even if you don't agree with those reasons). Claiming that the only people who need to be able to follow rules are concentration camp guards is ridiculous and inaccurate.
On the sexism point I totally agree, although I don't personally know of any schools that still require girls to wear skirts etc. That should be challenged through the appropriate channels.