> those creating the something "cool" simply because they would never fathom using the "cool" for "uncool" purposes

I can definitely imagine a ton of things going wrong with Web USB, and I think the spec authors did a pretty good job at bolting everything down that can be, while still shipping something actually capable at providing USB access.

And that's my point: Sure, fewer capabilities are always safer than more capabilities. But some capabilities are nice and arguably worth the risk, especially if the obvious alternative (blindly installing native applications) isn't much safer.