In a rapidly-changing marketplace, a certain level of diversification helps increase the odds of survival (it can be overdone; too
much diversification, and a company finds itself in charge of a host of projects in industries it doesn't know enough about to compete, which is what put Marvel on the rocks so badly that Disney was able to snap them up back in the day).
Not unlike in nature, a monoculture corporation lives and dies by their business being at all relevant in general, and the market (especially in the entertainment sector) is fickle.
