Lolicon is just fascination with young looking girls. It has little to do with pedophilia.
That's the western view as well. Lolicon is short for lolita complex and is used pretty much as their way to say pedophile in japan.
Western culture tend to pick words from japanese and focus on the most "positive" outlook of the word. Otaku is one example, with a lot of western people liking to call themselves "otaku" to emphasize their love of anime/manga without realizing that for japanese, otaku is a really strong and negative word that goes beyond just liking anime/manga.
Lolicon is the same, mostly because in western culture, there's a much more blatant dislike of pedophilia, lolicon got used to make a distinction with people who enjoy it in animes and manga, but don't want to be labeled as a pedophile. In japan, they do Idol videos with 12yo wearing skimpy swimsuits and those are considered to be legal when in most western countries, those wouldn't be tolerated.
In some way, it's kind of the same of how some people came up with "shojo-ai" to denote "yuri, but not too much yuri !"
Where'd it come from/start?
Don't really know, but when I was in Japan, I went to a couple maid cafe to see how those were and it was quite common there for girls making shows with a lot of "moe moe kyun". Heck, in Akihabara, I even saw one maid cafe doing street advertising with a couple girls in maids outfit on balconies doing the heart shape with their hands and speakers going "moe moe kyun !" endlessely. XD
It's just a word combination that sounds cute, not sure if there's any deeper meaning to it.
