Even if you're doing an "aimless" jam, you're still doing some valuable practice. Since we don't necessarily have an electronic equivalent to Rimsky-Korsakov's "Principles of Orchestration", even random screwing around is going to result in some insights about what patches, textures, etc work together, and which don't. And, of course, even screwing around still hones your patching skills, makes the process of knobs-n-wires more intuitive.
Plus, not recording things can also be a mistake, even if it's obvious that the "screwing around" in those cases is just that. But at the same time, if you have the take in your DAW...well, hell, ANYTHING'S fair game once it's on the hard drive. So it doesn't work in of itself...but what if you dubbed a few more things onto it? Or what if you used it as a layer in some other work? Or chopped it into loops? Or, or, or... This is part of the rationale Brian Eno's used for many years...true, it's resulted in a HUGE library of tapes of all sorts that he keeps track of, but if you know what's on them and how to work with those recordings, they're golden. In fact, whole albums of his have come out of this, with the most notable example being "The Shutov Assembly".