I'll confirm that 16 amp upper limit on L1 or L2 with our cars, and that should be the case on any multi-voltage equipment, AC or DC.
It is the amps that are limited because that electrical current flow is what heats up components. Voltage limits are a function of the insulation and isolation limits on those components. Voltage and current can be proportionately adjusted (one up and the other down, W=V*A) to achieve the same power levels, so designers pick a compromise point. One could conceivably charge a car with two tiny strands of copper connected to the 500,000 Volt Pacific DC intertie not far from me, but the equipment cost to step that 500 kV down to 330 V for my i-MiEV would be prohibitive... It would be nice to see only 10 amps of current delivering a 50 kW fast charge, though...
2012 i-SE "MR BEAN" 102,600 miles
2000 Mazda Miata EV, 78 kW, 17 kWh
1983 Grumman Kurbwatt EV,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
1965 Karmann Ghia Cabriolet