Before PA systems, cabs from the stage provided the volume; amp in the room. The size of the room or venue determined whether you needed a 2X12, 4X12 or a wall of 4X12's. With the development and advances in PA systems, silent or quiet stages have become more and more the standard leading to a need to discover how to get guitars into the mix.
Close mic'ing has been a standard born out of necessity, not out of what's ideal. It results in cutting out a lot of a guitar's tone or feel. We've just become accustomed to it, now defending it as the ideal guitar tone. I've seen rig rundowns of players that use as many as 4 to 6 mics in a live setting trying to replicate as many nuances of a cab/speaker they can.
I've spent countless hours trying to find a single mic position that replicated what I heard while playing at home through a PA system. I eventually found a position that worked but it still lacks what the FullRes seems to provide which I'm very excited about. With the new FullRes IRs, getting the complete sound of a cab through a PA appears to becoming more and more a reality.