that is one of the major reasons why companies there won't be open - they know full well that anything made publicly available would be cloned/copied within days.
it is not only a part of the competition common in all countries, there are unique reasons in China - millions of graduate engineers join workforce every single year, there are not that many projects they can work on. starting copying & cloning some existing stuff even at someone's own cost is a pretty effective way to get into the game.
> Ready access to media, yes, but also scientific papers, books, etc.
There is this old Chinese saying "Teach your apprentice and your own ruin follows" (教会徒弟饿死师傅), that has been telling a completely different story for thousands of years. When they don't even want to hand over tech know-hows to their own apprentice, why would anyone be expecting them to have the desire to share it publicly?