How about you post your trading profits over the past five years, and I'll post mine (that is when I started trading). Keep on truckin' with that Bund, you German stud.
one day, there will be a catastrophic event - even just a story published something like Pakistan nuked India. Sort of like the accidentally published (news was 6 years old) story about United airlines declaring bankruptcy. These seasoned traders who use extreme leverage will become bugs on the windshield. Then, they will not feel so clever. Some brokers who specialize in $300 day trading margins will become the blood in the street. They will be overwhelmed by the losses of their customers. $300 controlling $60K of emini? Not so clever on judgement day... Brokers like IB, who don't allow insane margins, stand a lot better chance of coming through in excellent shape. Customers may see a mega-Refco like event, but much worse.
"cheating themselves out of leverage" is no concern for those of us that understand the mathematics of risk of ruin.
I believe we are going to see a time in the not too distant future when those who survive will be those who knew how wise this advice was. Ignore it at your peril.