I've looked over my notes from the past upmteen years, and having the feeder pass through another tenant's space doesn't happen very often.
It's an interesting pattern; most often the gas, phone, data, and every other kind of line runs in a straight shot over everyone's ceiling, but the feeders are most often under the slab.
Where I've found the feeders passing through other spaces, there has invariably been quite a history of remodels and shifting spaces.
I have seen local codes that required all feeders (from the meter to the panel) to be in some form of pipe.
I fear that all this discussion has accomplished is to give the code-changers yet another opportunity to intrude on what has been a design issue. With their desire to 'conform' to all manner of other codes, they seem determined to address all manner of non-electrical matters.
