I believe he meant "people use their browser like they use an appliance" as in they don't know any details about it, just open it and use it as is.

What? Nobody's using their browser on an appliance (except for a handful of masochists with Samsung fridges). I said to most people their browser is on an appliance, as in they treat computers, phones, and laptops like appliances, in that they're mysterious boxes that do a particular job.

Hardly anyone is trying to hack their appliances, and the majority of people just lump their computing devices into the same category - it does what it was designed for and nothing else

A computer is an appliance. In the strictest sense of the word.