FWIW,
Been mixing ITB for many years, with a few exceptions mixing out to a console. I agree to an extent - mixing out to a console can often be an asset, but I think one of the points rarely acknowleged is what STYLE of music we are mixing. I believe for hard music (rock/metal/emo/etc) it IS better to mix OTB, as loud, distorted sounds (electric gtrs, etc.) tend to get ugly in digital: analog rules in heavy music, and it's strengths are slamming inputs, and summing. OTOH, mixing jazz or classical is often better ITB - less noise, colouration, and true to the performance. These are vast generalizations, and obviously subject to vary, but I think the biggest thing killing mixing ITB is smashing the hell out of the tracks: tracking inputs far too hot, running all tracks @ 0 dB, combining 32 - 100+ tracks of it - what do you think is going to suffer? Digital is not analog, and vice versa. They cannot be treated the same way, nor should they. Digital has it's limits, and we all realize what those limits sound like.
If we could ever get back to mixing music with dynamics, and not be bent on red-lining everything from input to output, we'd be enlightening ourselves to what's really ruining our mixes, and music in general...
My opinion only - YMMV greatly,