I agree nobody needs 400:1 leverage but your point is fundamentally incorrect. If your model your risk of your capital and not your buying power then leverage 100 or 400 shouldn't matter. The fact is anyone asking for 400:1 leverage is going to model their risk off their buying power and will blowup, that's why high leverage is synonymous with blowing up. If used correctly, the only thing that can screw you over is a liquidity squeeze.