They just think up how they expect something should work, or what they think something should be called, and try it. Then come in and ask why it's not working. They often exchange misinformation with each other without either party realizing it's false.
Then if you suggest to them they read up on the API for what they're trying to do, they won't... they'll just keep trying random things, trying to get someone to feed them the answer.
I think javascript is particularly bad for this, even though there are some really good books and references out there now.
This is not meant to disparage people like web designers who come at things from an artistic angle, but a lot of people who write Javascript are doing it in a tertiary role -- in support of HTML in support of producing a visual design that they envision. That these people don't have a solid foundation in programming shouldn't be alarming or disconcerting.
Ten years ago Javascript had a reputation of being a crap/toy language, largely for this reason. It really wasn't until GMail, IMO, when people started saying "Look, a JS app that doesn't suck!" and things kind of went forward from there.
Either you're talking about something different, or I don't understand what's wrong with such an approach... Although maybe 'experimental' is a better title?
...correction: On rereading your post a few more times, I realize it's just a misconception of terminology.