Because the bar menu didn't work well with gamepads. MRay (the UI dev) said so in the patch notes when it was released.
This is outrageous. If game companies relying on their prestige built of PC only titles plan on selling out the complexities of their games to better "welcome in" our lowlier console brethren than they need to stop asking premium prices as we (PC enthusiasts) are the ones making all the concessions. Game prices should be halved and standard game features which are cut to allow consoles to play should be stated in BOLD FONT up front and centers right there on the Steam page.
~Sons of Soon