I suspect that the main reason you find nothing but Windows or Mac computers in a big-box store is that the computer makers--and the store--want what sells. Various retailers have offered Linux computers, Walmart being one, but they didn't sell well and supposedly had high rates of returns. There are reasons this may have been the case (we don't know for sure), but these computers were mostly rather miserable machines, albeit very inexpensive. The buyers may well have not known what they were getting into and were just going for the cheapest computer.
one of those cheap, miserable, Walmart-sold machines. After VL 6 light, it's still cheap, yet for the first time no longer at all miserable. Original OS was a "branding" of Ubuntu. Updating mistakenly resulted in mis-installation of Ubuntu proper. If I didn't enjoy this kind of thing, I'dve returned it, too. Even properly installed, *ubuntu, even xubuntu, is too much overhead for a single-core 32-bit; VL light runs marvelously. The speed compares to vanilla NetBSD default (yep, that's right, TWM and nothing else). The installation and configuration, of course, thankfully don't compare at all.
The manufacturer, Everex, went out of business. The mobo maker, First Computer, is now shying away from VIA. Not that that's a bad thing, but costs go up for the switch to AMD or Intel.
This kind of machine is still needed. Walmart grabbed every machine they could get out of the defunct company, problems or no. Some large retailer, probably Walmart, would be very interested in a good package of really-ready-to-go VL light and this exact platform (I'd switch wireless card). It'd
definitely interest the vendors of the hardware and fill a gap and a need.
Wish I had time to do it myself.