Honestly the negative attitudes about John Riccitiello largely come from gamers who know basically zero about business or what a CEO even does. Some game ends up sucking or having questionable design decisions, and somehow that's the CEOs fault. That might be true at some tiny ass developer, but at a large company the CEO is largely concerned with the big picture, not what map size is appropriate for fucking SimCity.
John probably saved EA as COO, and then later on as CEO he was really good for the company. He had a bad year at the end, but still. Unless the dude is bringing the entirety of EA management and development with him, the shortcomings of some EA titles are irrelevant to what he might do at Unity.