Why does Julia support `::Vector * ::Matrix`?

Fear not – I would revolt, too. Even I never imagined to remove x * y' for outer products. But y' is a Adjoint{<:Any,<:AbstractVector}, which we can (and do) specialize beyond what we do for general AbstractMatrix. There isn’t an incompatibility here.

But like I said: there’s little harm in the current behavior, no possibility to change it in v1.x, and still almost no reason to change it beyond that.