It's the same kind of distraction as autoplaying videos or picture-in-picture annoyances like YouTube's auto-minimizing window. The mechanism is the same. It's a thing moving in some part of the screen and being distracting, only in this case they provide even less value since they're nothing more than decorative doodads.
There isn't even an argument that doodads like these can placed on websites in an attempt to monetize users, like ads, where all the debate about sustainable sources of revenue and the ethics of adblocking come into play. They serve no material purpose at all except to be distracting.
Animations of any kind, even the ones that are finite in lifespan or simple page transitions, already annoy me greatly. If we lose this front, where random businesses start adding things like this only because the web platform has sufficiently advanced technologically to allow it, and a majority of users become desensitized into believing it is "cool" and shifting the the baseline of the web such that this majority now expects and might even want this kind of behavior, it would surely become another unnecessary annoyance. I feel like this has already happened with Metro/Flat design and the death of skeuomorphism (more or less), and also the overuse of animated GIFs in blogs.
But there's nothing making it outright illegal, so I'm not sure what would stop them from doing so at this point. We can't exactly go back to Web 1.0 (nor should we) - that kind of design is opt-in now.
There isn't even an argument that doodads like these can placed on websites in an attempt to monetize users, like ads, where all the debate about sustainable sources of revenue and the ethics of adblocking come into play. They serve no material purpose at all except to be distracting.
Animations of any kind, even the ones that are finite in lifespan or simple page transitions, already annoy me greatly. If we lose this front, where random businesses start adding things like this only because the web platform has sufficiently advanced technologically to allow it, and a majority of users become desensitized into believing it is "cool" and shifting the the baseline of the web such that this majority now expects and might even want this kind of behavior, it would surely become another unnecessary annoyance. I feel like this has already happened with Metro/Flat design and the death of skeuomorphism (more or less), and also the overuse of animated GIFs in blogs.
But there's nothing making it outright illegal, so I'm not sure what would stop them from doing so at this point. We can't exactly go back to Web 1.0 (nor should we) - that kind of design is opt-in now.