Hey, I used to use it! :P I came from BASIC background. VB6 was supposedly good for rapid prototyping of GUI apps (esp CRUD variety). I found it would boot up in 1 second, deploy new project in 1 second, and load new app in 1 second. It was also safer so no constant blue screens over common functionality. It also could wrap foreign code in less safe languages which I could still write in an industrial BASIC. One could also export the GUI to code in different language.

Became one of my favorite toys. I'd still use it for GUI prototyping if it was FOSS and kept getting extended. I found even lay people could learn it well enough to get stuff done. Long after, I learned what horrible things lay people did with it. Yet, they got work done and got paid without the IT budget and staff they would've preferred. (shrugs)