Regretsy is a site that makes fun of things on Etsy. This is how they describe themselves:
"What is Regretsy?
Regretsy is where DIY meets WTF.
The majority of objects d’fart posted here are collected from the web site, Etsy, though I sometimes feature crafting failures from other sites.
I also will sometimes post things that are just incredibly odd and wonderful. So while not everything here is terrible, it is always WTF."
I think that they just didn't think your dress was steampunk. It was filed under "Not Remotely Steampunk."
They also say this on their FAQ:
"I’m pissed off at a seller you featured. I’m going to go harass them on Etsy. Is that cool?
No. We only encourage contact if you’re going to buy something from an Etsy seller. If you harass or threaten someone we feature, and they report it to us, we will delete your account."
You might want to contact them about the harassing messages you've been getting. Report the people who are sending those messages to Etsy too.