NEW YORK ( TheStreet) -- JPMorgan Chase's ( JPM) outsize quarterly profit should put to rest any questions why Chairman and CEO Jamie Dimon is spending so much time on Capitol Hill fighting new bank rules. Dimon credited the investment banking unit for pushing JPMorgan profit above Wall Street's expectations. Meanwhile, consumer banking pretty much bombed because of big credit losses. Today's earnings suggest that JPMorgan Chase is only a good investment because it combines both investment banking and consumer banking. An argument could be made that proposed restrictions on proprietary trading could destroy that balance. What would become of the Chase and Washington Mutual operations if the bank had to make a choice between the $2.5 billion net income from investment banking and the $131 million net loss from retail services? And if such rules were in place during the financial crisis, JPMorgan might not have been allowed to bail out WaMu (a compelling argument for angry WaMu investors to support new regulations). Leaving aside the whole WaMu debate, today's JPMorgan earnings may steer the banking regulation debate to the question of whether the balancing cycles of investment banking vs retail banking are beneficial. That is, after all, the whole logic of the JPMorgan - Chase combination. Ditto for Bank of America ( BAC) -- Merrill Lynch, another union born out of the financial crisis that might not have been possible under the new bank rules being discussed. Bank of America earnings later this week will no doubt tell a similar story to JPMorgan. Maybe Citigroup ( C) offers a model for compromise with its move last year to put its Smith Barney brokerage business into a joint venture with Morgan Stanley ( MS). Perhaps megabanks can transfer control of the proprietary trading divisions without giving up all the profit? No matter how it's done, though, unwinding these banking behemoths won't be easy. And when we see results like JPMorgan delivered today, it's easy to understand why folks like Jamie Dimon wouldn't want to. Who can blame Dimon for defending his right to deliver multi-billion dollar profits. I get that -- but let's not forget that the lust for profit is what brought the global financial sector to the brink of collapse.