It appears boehner was trying to do obama’s bidding but 50 or so Conservative Republicans and almost all the democrats wouldn’t let him. The Conservatives and democrats want all or nothing it’s just that they disagree on what the all is.
or......
In order to keep the House in control, conservatives were designated to vote with the Democrats to kill the bill.
by so doing, the House keeps control of the money. There was no risk in the gambit, it was a sure thing
After the move, the Democrats in both the Senate and the House are responsible for ending the DHS. The government was not shut down, the DHS was ended until a new department can be legislated