Because Bin bags were made to line the bin or trash can, outfits are not usually made of bin liners, but cotton, nylon, polyester, and other such fabrics. Your interest is unusual not usual, unfortunately for you not many people share this interest on here, but I hope you find someone that does.
I have to know, what is with you and the trash bags, is it a sex thing? Because if so it's a strangely specific fetish, unless it's part of a larger plastic kinda thing, like people who like rubber
No it isn't, I just am passionate about wearing them and I also think it should be part of mainstream fashion. Plus a lot of people don't know about using them as clothing.