IMHO, the problem is not in the abilities of sound men or the capabilities of the technology they use, it is what they themselves are hearing in their heads and think the audience wants to hear.
It's very much about the technicians doing the mixing. I've had an experience recently to "enjoy" a hard rock concert at a mid sized venue here in Nashville. The opener was a local group with perfect sound. The second act was a charting metal group and the sound was so poorly mixed that you couldn't hear anything for the giant screaming wall of noise. It was horrible. The main gig (Seether) was mixed perfectly again, with every note and every word clear and the volume loud but nothing stupid.
It was very obvious that it was about the sound team's inexperience and makes me reconsider returning to the venue at all.
well some of them.