Oracles culture of work from home, no accountability, responsibility coupled with outdated skills are key reasons why ppl do not leave. Also traditionally Oracle has not let go people(except.for.sales). The on-premise products had demand customer used to call Oracle sales to close deal. All this resulted in workforce not being used to working. The hikes used to be less but they were there and the initial salaries used to be better than going on market rate.
Who likes change, it comes with lot of risk. The easy way out is to Oracalize anyone who joins company and maintain the status quo.
And remember what ever people say culture is always top to down. Till top layer remains intact new workforce would be Oracalized. The ppl at top who are being asked to go or have left are the one who wanted to change themselves and the culture.
Unfortunately for Oracle some of few who joined at the top level are not the ones who have been successful in turning around companies-they are still trying to use same failed tricks of trade at Oracle.
Not rocket science but no one wants to admit and accept the root cause of current state.