So, what's the driving force behind this? They're not doing it out of the good of their hearts, so I see three obvious possibilities: making the website a more

So, what's the driving force behind this? They're not doing it out of the good of their hearts, so I see three obvious possibilities: making the website a more attractive place to advertize, external pressure hurting their image (like that time they banned some subreddits only after being featured on CNN) or trying to appeal to more women. Did I miss anything? I assume it's some combination of the above leaning heavily towards advertizement. Considering the number of house ads I see them running, and the anecdotal things I've heard about advertizement sales on 4chan or other uncouth websites.