How come Google Maps isn't available to App Store accounts from Israel?
Your apple ID is registered in the Israeli Store. The application is not available in the Israeli Store, so you cannot switch to the U.S. store. 

Two items need to happen for an App to be listed in a certain country:


The developer of the app (Google in this case) needs to register with Apple to fulfill all the legal and contractual requirements to sell in each country they choose to have a presence for any of their apps to be sold.
They need to submit and have Apple approve each specific app for each specific country. Most developers push all apps to all eligible stores, but they don't have to choose to do that even though they could opt to do that.


Let's leave the speculation on who / what / why to either company (Apple and Google) to address in particular, but we can certainly discuss the mechanics of how the app stores work without getting into opinion and conjecture.