It makes sense for vinyl, to prevent vertical groove excursion at LF, but for digital, which has no inherent highpass effect nor does it restrict interchannel phase at any frequency, I can't see the point. LF out of phase information adds depth - I forget which reverb designer (David Griesinger at Lexicon?) says that it adds depth and dimension, and is found in real rooms quite often. IMHO, you might as well go all the way to mono if you need to eliminate that.
But, for cutting vinyl, where you have to stuff the mix into a small box, it makes sense.