"Most servers/switches accept DC power"
Which they then feed into a switchmode power supply to convert to whatever they actually use internally.
Meantime you pay 10 times more for DC PSUs AND given most DC feeds are based around 48V (telephone exchange standards) you have to spend 10 times more for feeder cables to the racks as they have to be substantially heavier to carry the higher currents that lower supply voltages entail.
On top of that should you draw an arc at any stage you'd better hope that noone decided to cut corners on power switches (which have to be current-derated by 80-90% for DC vs AC in order to ensure arcs are quenched) or fuses (same deal. High current DC fuses are larger than their AC equivalents because AC arcs are self-extinguishing every half cycle, whilst DC arcs have to rely on the endpoints being pulled far enough apart to quench the arc that's been maintained through ionised air)
That means that your electrical standards and precautions for "Low Voltage" high current DC have to be substantially more robust than for AC mains. I've seen more than a few spanners end up as a shower of molten sparks because someone got careless around DC busbars - molten sparks which have the potential to cause fires or secondary damage should they land on anything flammable or be drawn into the air intakes of a blade server (think of it as an injection of conductive iron dust and you won't be far wrong). That was OK in the days of concrete-floored Strowger switch rooms but not so wonderful around high density electronics.