It makes sense to me because the amount at issue is so small. Passing the law -- as long as it is accompanied by a very strongly worded statement against the President using words like embarassment, immature, dishonest, caring only about reelection not the country", etc., -- would emphasize how exactly how petty and small the President really is. It would point how how unserious he is about tackling the deficit, and show that he needs to be replaced.
Instead, we go to the mat and spend political capital on people making more than a million paying a lower rate than people making $100k. Sheer stupidity on our part because that's not even a principle worth defending.
There already is a Buffet Rule. It’s called the Alternative Minimum Tax.