Why would there be? They massively profit off of its existence.

Only barely 3% of the Desktop OS market share is Linux. (That's regular consumers)

Something like 80-90% of corporate servers are Linux. (That's big business, not even just big tech)

Sometimes I think Open Source is unintentionally the largest transfer of wealth generated by volunteers from the working class to the wealthy in history. The corporations get off the shelf software they can run for free and they don't have to pay a license for and they make money using it.

just look up the history of java code

Here is a decent starting point in answering your question (the article has a few examples that are mostly related to open Internet protocols): https://en.m.wikipedia.org/wiki/Embrace,_extend,_and_extinguish

SCO vs Linux.