Money. Anecdotally that's the primary reason Oracle do anything.
I worked for a tiny startup (>2 devs full time) where Oracle tried to extract money from us because we used MariaDB on AWS.
If you think this sounds ridiculous you probably got it right.
(Why? Because someone inexperienced with Oracle had filled out the form while downloading the mySQL client.)
Money. Anecdotally that's the primary reason Oracle do anything.