Senators want to kill Fannie out of revenge against former fnma lobbyists, not to "protect taxpayers".
I can understand why senators are mad. Under the powerful Senator Barney Frank, Fannie got some special treatment, as Frank's Husband was a FNMA executive.
So, many fannie mae lobbyists were hired and blocked the Senators doors for other lobbyists (on purpose).
To get revenge on FNMA, Barney Frank, and the lobbyists for fnma, several senators (Corker, Warner, etc) decided to "kill fannie" and hired a former countrywide worker to write the kill bills. And, they want to do this at the expense of shareholders who had nothing to do with the actions of fannie mae lobby, or Barney Frank and his lover.
The Senate is acting out of revenge, not concern to protect taxpayers as they pretend. Its political scandal at its worst.
Source: This is my personal interpretation of a conversation on April 8 with an Aid in Senator Kirks office, that I attended with "Ann" and Mr. Frank Fosco.