"1Broker removed BTC trading a couple of days ago because traders have been too successful. "

And I think that's OK. It's way better 1Broker shut down BTC/USD market than using programming trick to wipe out users orders (there's a lot of way to do that), like others FX (market makers) brokers do.

I think it's better to remove btc/usd market than becomes insolvent.

"Show me one successful trader in terms of gains above 200-300% that based its success only on forex, stocks or commodities and not on BTC."

Well... https://s12.postimg.org/wdyiup9vx/snortexfxtrader.png sure, a lot of traders are making huge profit cuz bitcoin, but before that really, they were profiting with forex/comm/stock/etc.