Last modified: 2014-06-09 18:06:52 UTC
"View history" is a very specialized action. Does it really deserve an own tab in that expensive space? By having one option less we would give a bit more of potential attention to other options. Also, we are considering other candidates for a tab, and maybe here we could save some space.
"View history" is being moved to dropdown menu magically when the screen is too small to fit it. This used to be part of the Vector extension, but is included in core since bug 46513 was fixed. While specialized, it's also highly important one for editors and stowing it away looks like bad usability to me.