The real problem is that designing for different screen sizes, especially with responsive design, is very difficult. For my personal projects, screen size is the factor used to determine layout. Mobile/tablet/laptop/desktop is irrelevant. My goal with smaller viewports is to make the layout as similar as possible, without the user having to scroll horizontally. Because I don't want to change the layout too much, I do…
I am genuinely interested in why. The only reason I can think of, is that they may me unintuitive, but I think this is becoming less and less of a problem.
Hamburger menus are an accepted and pervasive design element. That does not means it’s good design, but it means that users are familiar with the concept. Familiarity goes a long way to ensuring good UX.