From a link in the first article:

During their early days, the prevalence of female participants and their subjects of interests in dōjinshi markets had made male dōjinshi artists felt alienated. In response to the freedom that yaoi dōjinshi demonstrated in exploring eroticism in the relationships between male characters from popular anime series, certain male artists such as Hideo Azuma and his colleagues were motivated to made their own dōjinshi that explores eroticism of female characters drawn in cute, cartoonish style (Galbraith, 2013: 288). The work of Azuma and company, titled Cybele (Shibeeru), was then regarded as a pioneer that initiated the popularity of lolicon themes in the 1980s, also known as the lolicon boom (while yaoi also had its own boom in that period). Because of that, Azuma is renowned as the father of lolicon.

So basically, lolis were invented because a bunch of cishet dudes got butthurt that doujinshis catered towards women and wanted to, in their own words, "drive yaoi out of Comiket!!!" I suppose one shouldn't be too surprised a bunch of pedos turn out to be reactionary as well.