Because as far as I'm aware none of them have been convicted of a criminal offence.
"Police investigations into Uddin's and Paul's expenses were dropped after a Lords committee clarified the rules on expenses in January to allow peers to justify calling a property their main home, even if they had visited it just once a month."
"Lord Strathclyde, the leader of the Lords, said: "I was shocked and appalled by these cases. There was a clear and serious abuse of taxpayers' money. The penalties recommended would be the toughest handed out by the House of Lords"
Clearly Lord Strathclyde also thought they should be in the poky,and you do not get suspended unless you break the rules