Sony apparently likes Nintendo doing well, because they create a new audience of people for them to target eventually, based on what Shuhei Yoshida said
"Nintendo is bringing a younger audience into gaming, and some of them when they grow up, might graduate into more mature systems like PlayStation or Xbox. Of course, they have huge respect for what Nintendo does in terms of how Nintendo should be doing in the industry. We all felt like it's great to have Nintendo to continue to be successful so that we can continue to grow the industry."