I think a less-brittle claim would be that they are at best a extraordinarily leaky and idiosyncratic layer of "abstraction" enough that for certain tasks you w

I think a less-brittle claim would be that they are at best a extraordinarily leaky and idiosyncratic layer of "abstraction" enough that for certain tasks you wouldn't want to actually use the term. It's like saying human personal assistant Bob is an abstraction over your calendar and shopping list. In other words, it depends where the people talking have placed their cutoff point for a good abstraction versus a terrible and unwise one.