I hardly ever used them when I used VS, so I don't see why I would be cursing their lack now.

Were you clicking around the menus all the time or using a heavily modded keymap? Building, running, almost all of the debugger commands, viewing property pages, switching between code and designers, all make heavy use of the function keys out of the box. Those are pretty common tasks.

VS would probably repurpose the ribbon to provide debugging keys at that point.