I do agree with you that this culture war didn't suddenly appear and divide society as a whole ex nihilo, but that's because nothing ever does. Movements start small and expand That's true of the particular brand of progressivism at hand here as well as the GNU movement or even the adoption of Linux and open source more broadly (those could sort of be said to have originated in a "culture war on the internet").
And I think it would be hard to dispute that the West has seen a very hard cultural push by progressives in recent years. Compare [1] to [2] for example. These are not equivalent examples and they are not meant to be. My point is that the sort of push seen in [1] clearly has implications outside of the abstract internet (Twitter is part of the Internet, but the point is that it has impacts on real life in a way 4chan doesn't). Also, Islamic stuff is perhaps the most obviously conservative stuff, but it's by no means the only one. Asian cultures in general are much more conservative than the West too.
[1] http://nationalpost.com/news/canada/steve-ladurantaye-editor...
[2] https://np.reddit.com/r/AskReddit/comments/6jbyu1/serious_pe...