Welcome to Android Central! What SSID's do those hotspots have--in other words, what are they called? Not all available public wi-fi hotspots are actually connected to the internet. For example, a while ago, there were a whole bunch of hotspots called "Free Public Wi-Fi" that didn't connect to anything--I think they were leftover from a failed service.
Are you sure those free hotspots don't require some sort of login in a browser page? Open your browser and try to access any site like Yahoo. If the hotspot requires a login or an acceptance of terms and conditions, you won't be able to connect to the internet until you get past that page.