I agree, the concept is non-intuitive.
Yesterday, I tried to explain to my grandma how to check for train and bus connection on her new iPad using the app provided by the public transport company. Of course, they had a hamburger menu to hide all the gazillion things you can do with the app, but my grandma was not able to find it and even then, she struggled with opening it because it was small and jammed into the upper left corner.
I got used to looking for things inside the menu, but I can see how many people aren't.
Plus, I like the simplicity of tabs