hypercrites

Why was Jamie Dimon testifying before Congress today?

You're exactly right. Jamie Dimon ran a private company that made some bad business decisions and lost a bunch of their own money, and for doing that he gets summoned to Washington and becomes a reluctant participant in the political "look at me!" show that congress puts on all-too-often.  Sadly, the left is completely oblivious to this fact and just laps it all up.