It's really very, very simple.
She can wear what she likes.
We can think what we like.
(I wonder if it's possible to say that in fewer words ?)
The added kicker is there's no law requiring anyone to think anything about anything - nor indeed to disclose that to others.
So Andrea Leadsom can wear what she likes, I can think what I like about that, and the world goes on.
Can't really see the problem. Unless it's because I refuse to agree with some, or disagree with others 
The real problem is when people say "she can wear what she likes" they are lying. We all know she can't. If she were to rock up in an SS Obersturmfuhrer uniform, I'm sure some people who are defending this look would suddenly say it's "not appropriate" (i.e become hypocrites).
So it's really "she can wear what she likes (within reason) " ...
But as several posters have already noted, who gives a shit what someone is wearing when they're grinding their boot into your face (metaphorically) ?