Members of Congress and ex-presidents get substantial pensions and Congressmembers get special private medical insurance. Most of them are wealthy to begin with. Thus, the sequester negotiations are really just theoretical to them as they won’t personally be affected, regardless of what happens.
So, instead of finding actual solutions to the budget impasse, they attack the other side to score political points (and boost their fundraising efforts.) It’s just a game to them. Congress and the president have known for 18 months that sequester is coming and have done little to stop it. They live in protected bubbles, so why should they care? And they don’t.