Sexualisation is an interesting, but difficult topic to discuss, because our perception is influenced by what we are used to.Would you mind giving some examples? Maybe there are some in there that are slipping my mind…
We are a culture formed from thousands of years of history. Throughout all of it, the vast majority of creators and consumers were straight men. We as humans tend to draw characters we find attractive, almost without thinking about it. Combine that with a party bag of misogyny and oppression that also made up our past, and you get a timeline where the vast majority of women in media are sexualised. This influences what we view as normal today.
When I was a young teenager, I didn't consider the fact that I had to shave my entire lower body to go swimming anything sexual - but this discomfort is unsurprising when you consider that modern women's swimsuit was designed by a man in a period when legs were in. No doubt if we came from a matriarchy, they'd be more options for comfortable shorts in store. We don't consider one pieces sexual because they are so common that it's no longer a sexual choice, but they are sexualised.
All this backstory to say that I agree that a micro skirt and thigh highs are a sexual outfit. As a result, most female Vocaloid outfits are, though nothing out of the ordinary, quite sexualised.
It's so common because it covers Japan's most popular fetishes (school girl & zettai ryouki), and companies view the idea of not sexualising a female character like they view burning money. It feels normal to us because we grew up with it, so a female character that isn't sexualised stands out more.
Now, you can all draw your own opinions on the pros and cons of this, remember this is a sensitive issue that isn't entirely on topic for this thread (and I am contributing to that ). My closing unpopular opinion is that I would like to see more variety in female Vocaloid designs, exploring avenues that aren't tied so closely to what people find attractive - there's so much we, and the art world as a whole, could explore. I want undead Lena Horne V5. Maybe you'd prefer the next 50 male Vocaloids get thigh highs. Either way, I'm ready for a switch up.