Did you just call the US underdeveloped?! Because that's where most of the under 4GB devices are Sure, most are intended for emerging markets, but never reach them..
It the shoe fits. - 2008 (10 years ago) was the year Netscape was finally discontinued by AOL and at the time I recall I couldn't buy a computer with less than 4 GB (64-bit). The PC I am typing on this even now has 8 GB and was from that time point.
Perhaps if you were building your own, maybe. But if you were walking into your local Best Buy and looking at a HP or Compaq or Dell at the time, I recall nothing having less than 4 GB (64-bit). Let's be honest, the majority of consumers wouldn't know how to build themselves a computer back in 2008 (and those of us who did, still could be lazy).
How does that compare to 50 options with 3GB or less? I'd say it proves 4GB was just taking off hence the slightly more options (27 vs 21). Only after Windows 7 release in the next year 4GB became "the norm", but there were still plenty computers sold with less in the following years (up to 2013-2014). Many of those 4GB offers even came with.. 32bit Windows Vista / 7 / 8. And FYI, bestbuy had (still has?) unified offerings country-wide. If something was not on stock, it was available on order. It's quite a different picture than your outrageous "I couldn't buy a computer with less than 4 GB (64-bit) .. back in 2008". My 2008, 2GB RAM htpc made me do this roast