I thought, when I traded up and bought my Janome 11000, I'd never need another machine. Then I bought a Featherweight 221. Learned about the free arm Featherweight, and now have two of those. Also a black longbed 301, a White VSII treadle in a Twiggy cabinet and a Singer 115 in a parlour cabinet, and another 115 head that I want to turn into a handcrank. There's a Janome 1600 on my Grace Pinnacle frame, a Janome 3160QDC that I bought for classes that require more than a straight stitch and I thought I was finished. Oh, and a serger and a Janome MB4 for embroidery. However, I now have a Singer 401 in a cabinet that I'm enjoying very much. I doubt if I'll ever buy another modern computerized machine again. I sew quite well with the mechanical all-metal Singers and I can maintain them myself. And they're easy to find if you need a parts machine,etc.
I can forsee parting with some of my machines, and it'll be the plastic ones that go first. However, my collection is a source of joy to me and I don't have any other collections. I don't like a lot of clothing,shoes, jewellery, etc. It's my "thing" and I'm proud of it. I see no need to explain my owning several machines. They all work. I use them. I enjoy them.