The line length of readable text is quite limited, yet our monitors are wider than they are high. Since websites still contain a lot of text they profit more from getting the full screen height than from getting the full screen width. Hence vertical tab bars.
I'm not a fan of the giant pictures they use as representations of tabs when my tab bar fits ~40 tabs in one screen height. But I guess that heavily depends on user preference.
I'm not a fan of the giant pictures they use as representations of tabs when my tab bar fits ~40 tabs in one screen height. But I guess that heavily depends on user preference.