It's worth noting that the modern kilt is designed to work in. As I understand it, they used to be ankle-length, but when the Industrial Revolution happened, longer garments tended to get caught in machinery, so now kilts are all knee-length. Whether or not this development also facilitated break-time intercourse and/or pooping directly onto the factory floor is a matter for historians.
It's also worth noting that while they are currently a unisex garment, it wasn't too long ago that trousers of all sorts were considered specifically masculine clothing. By the standards of two centuries ago, nearly all the female characters in my comic would be wearing scandalous manly attire.
(Of course, by the standards of two centuries ago, there's a lot in Leftover Soup that would be considered scandalous, if not entirely alien and inexplicable).
Which is to say, Ellen is kinda right and kinda wrong about cross dressing. Culture and male privilege and power dynamics and fashion are all constantly in flux, both in time and in space, and even something as simple as a pair of pants in one context is always going to be interpreted differently in another context. Her statement is perhaps most correct if one views Patriarchy primarily as a system whereby men - and those who make use of masculinity - have all the freedom and all the power over women. If one views Patriarchy as a system wherein men are trapped and constrained by their masculinity, however (see any political function or red carpet event as proof that we have far fewer sartorial choices than women), then wearing a dress can be a very bold and decisive act.
In any event, regardless of one's biological sex or gender identity, I do think that everyone should wear decidedly masculine clothing in public at least once and decidedly feminine clothing in public at least once in one's life, if only to see what each experience feels like. Who knows, you might learn something about yourself.
You can probably skip the experience of pooping on the floor, though.