The most important, and sufficient, reason to learn Swift - or anything else, for that matter - is curiosity. I don't like working with people who are not curious about their craft.
Its really unnecessary to learn Swift -there are a plethora of other, better ways to build apps.
But if you want to keep up with the joneses - while delivering Apple a perfect 'big stick' to keep developer mindshare locked into their platforms - Swift is a pretty sweet deal .. for Apple.
But if you want to keep up with the joneses - while delivering Apple a perfect 'big stick' to keep developer mindshare locked into their platforms - Swift is a pretty sweet deal .. for Apple.