I would say Microsoft, they brought nothing good to the industry.
At the beggining i thought it was good cause they were having alot of SEGA games and it was looking like a spiritual sucessor... but quickly things turned for the worse. Nowadays its FPS central. A genre im not fond of.
Their big IP's dont come from their internal studios originally aswell. They are buyouts.
Nothing would be lost if Microsoft exited the games market.