[RC-Monster Mike]

1/10 onroads use high Kv motors, but they are small....and they still have high current spikes. A Larger motor will see much larger spikes that many/most ESCs are ill-equipped to handle. Generally, increased power needs are met with increased voltage(1/8 use 4s and above to illustrate). As the current goes higher, it becomes harder to get the current to flow through the wires,connectors, solder joints, battery tabs, etc. so increasing voltage allows more power to flow at the lower current.