The article mentions it in passing, but Oodi is an important stop for parents with babies. The third floor is quite often packed with strollers.

Sure you can hang out in any cafe, but I find it valuable to have a place like Oodi that's free, easy to access, and built with kids in mind. When taking the kids on trips in Helsinki, we often visit Oodi to eat lunch, just because it's so easy. Or the whole trip might be just to visit Oodi, eat, and grab a couple books. Of course the central location helps a lot.