Pretty much every President and Presidential candidate has talked about infrastructure for decades. Talking about the broad concept isn't new or useful, actually having a useful substantive policy proposal is what is needed (and not just in one office, since it takes a number of different institutions to get the kind of things done US infrastructure needs.)

The problem isn't an absence of talking about infrastructure, it's bad plans, good plans that don't get passed in Congress or that get underfunded, and members of Congress not being interested in infrastructure outside their own district except to the extent that that it provides an excuse for pork-barrel spending in their district.