Feeding arbitrary sequences of samples into dbscan and deciding that because dbscan produces output, there is causation (or, that there is an underlying phenomena that can be captured in some type of model), is ridiculous. And there are tons and tons and tons of natural phenomena that will be happy to produce clumpable inputs all the time, with no underlying behavior (including noise).
I'm sure there are also tons of interesting models of human behavior that you can make out of some set of observations of human behavior via clustering. But just because you feed some data to an unsupervised learning algorithm and it discovers features doesn't imply that those features have any useful descriptive power to help us make sense of the natural world. THAT's anti-scientific thinking.