This is not unique to XOM, but loyalty is dead. People can be loyal but not companies.
Sometimes people stay because they like the work and like the security. But that is complacency. Over the long haul, loyalty leads to exploitation. When opportunities come knocking or when your career/ salary stagnate, don’t hestitate because of a sense of loyalty. The company will drop you when times get tough or when the next shiny new toy comes along.