The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage.NEW YORK ( TheStreet) -- In 2007, the banks gambled on mortgages and lost, causing the largest global recession since 1929. They then gambled on European sovereign debt and lost. And now we hear JPMorgan Chase ( JPM) just lost $2 billion on a derivatives' bet. Should this not be the last straw? There are important lessons to be learned from all this, lessons the bank lobbyists don't want anyone to hear.