We can understand your concern there and it is understandable. But we along with many developers follow the philosophy that logo size remains constant in all viewport and it should be made to fit in all screen. For example, see these two themes https://wordpress.org/themes/responsive ( most downloaded theme on wordpress.org ) and http://theme-fusion.com/avada/ ( most downloaded WP theme in ThemeForest ) .
Off course many other developer thinks that logo size should be big or smaller according to screen.
If you can provide us the demo link of your site then we can provide CSS which should resize your logo according to your screen size.