Back in the day (i.e., the period you're talking about!) Radio Shack -- back when their name was two words, rather than "RadioShack" -- sold bare components, breadboards, and IIRC even blank circuit boards, as well as all sorts of textbooks about electronics and various projects. They certainly weren't focused on the "makers' market" but they very explicitly catered to it.

And, really, I don't know if there's anything like that today. I'm not sure that a store like the original Radio Shack could exist anymore; I mean, RadioShack may have given up on the space for a reason, indeed the reason that you cite (it wasn't big enough to be sustainable). But that doesn't mean that its departure isn't a genuine void, however small.