Keep in mind that if you don’t have Internet connection, features like weather-based control and automatic time zone / DST detection will not work. You also can’t access the controller remotely if you are traveling away. For most users, these are the most valuable features of OpenSprinkler.
Similarly, I would argue that to control the device through an USB cable defeats the purpose of having a web-based sprinkler controller.
What’s included or not included in the package is CLEARLY indicated on the product webpage:
I am sorry if you missed those when you made the purchase. One reason that transformers are not included (as specified on the product page), is that you likely already have a sprinkler controller and you can reuse the transformer because all sprinkler systems have the same electric spec. Also, it’s difficult for us to stock transformers for different countries that have different mains voltage.
I don’t think it’s surprising that ‘router is not included’ — how would you expect the controller to get connected to the web, if you don’t have a router? You might even argue that we should include sprinkler valves, but I think it’s common sense that these are provided by you. OpenSprinkler is just a controller (like a thermostat is just a controller for HVAC system), it doesn’t include the whole system.