The question is why every time the user wants to look at a map she needs to let Google know, using computer network access for which the user must pay.
Paper maps or maps stored on physical media do not have this requirement. The map company may "own the map" but the purchaser can look at the map anytime she wants, without any ongoing expense to keep the map company abreast of her travel plans.
I do not not use an "account" or "log in" to view free maps, so I just take screenshots as a quick workaround.
Users wouldn't be prohibited from doing this for much the same reason people aren't prohibited from making personal copies of pages from books they own.
If you take a picture of Google Maps and then host it on your website without approval/paying Google and get caught you'll be hearing from their copyright lawyer.
I could take a picture of a map and share it on my LAN via httpd so all my computers can access it. I am the only user on the LAN.
It is not the "website" aspect that would implicate copyright, it is the redistribution, e.g., via a website on the public internet.
My original question is being misunderstood. It is not about copyright or what rights Google has in maps. It is a question about why Google attempts to force users to contact them every time the user looks at a map.