Good to have if your team isn't playing in every game of the Season, or if your team has been eliminated from the Playoffs. I mean, if you watch enough of a particular team sport, other than just games that involve your favorite team, it seems obvious or natural that you could develop some degree of "like" for certain other teams. Personally though, I'm just as likely to "like" certain other teams not only for the team of players but also for the city if it's a city a like.