Competition is great for the industry. It spurs creativity and innovation, ultimately benefiting the consumer. That's why I love the bitter rivalries between the three major platform holders. Sure, Nintendo has distanced itself from Sony and Microsoft over the past several years, but the Big N is still fighting for gamers' dollars and time regardless.
Each home console has its legion of loyal fans who rally around their hardware of choice and its lineup of exclusive games. The reality is that gaming is expensive and gamers have only so much time and money to dedicate to the hobby, so not everyone has the luxury of being a Sony, Microsoft, and Nintendo gamer simultaneously.