You might be surprised what DIY mining pushes users into.
I'm quite certain DaT is well aware of what "DIY" miners get up to

5760W equals less than 4 x 1500w at the wall .. so you'll use only 3 outlets at max from the strip leaving about 1.2kW spare.. With all those C13 outlets available on the PDU one may think they're good to draw more, when in fact they should be taped out. With 20A circuits to have less spare (about 840W).
And if they're loading up their PSUs to that limit, they're likely to just use at 15% de-rated instead of 20% and load 4 outlets at 1,500W. But they're likely not using 1500W at the wall draw, so this is really a non-issue.
Anyway, all setups are good as long as the end user monitors the currents and size their stuff so that they don't burn their house down. I like the 240V setups because they load the two 180 degree phases equally and you don't lose much having an unbalanced system.
Precisely. Arguments can be made for any side; personally I prefer switched PDUs on 30A drops.