You could say that about everything almost. There are billions of people that don't watch soccer, football, baseball, basketball. There are billions that aren't *insert specific religion*. Are these all niches?
What would be the context of making that comparison?
Here, we are looking at the CEO of a large corporation talking to investors. The context would be other business markets and opportunities which investors would be considering. I already pointed out that the smartphones market dwarfs the gaming console market, as an example. He's saying that the physical gaming console market is always going to be relatively small and thus have a limited scope in terms of potential customers.
Let's say Sony has a home console with an installed base of 80 million after good sales over a number of years. On the other hand, smartphone adoption is projected to top 5 billion relatively soon. Which market has the most potential? What if we include other smart devices capable of streaming?
If the Playstation brand is doing this well in a relatively tiny market, what if the possible scope increases exponentially? It's an argument intended to entice people to invest money. It's no big deal and there is no reason for anyone to be offended for the sake of console gaming or to argue over the word "niche."