Only because they haven't bought a Riptide yet

Rico says it's a cogent editorial in The New York Times about the latest military extravaganza:

The Republicans’ fervor for saving the taxpayers’ dollars doesn’t extend to one of the Pentagon’s costlier failures — the Marine Corps’ new Expeditionary Fighting Vehicle (EFV), a hybrid landing craft and battle truck.
Twenty years in the making, the vehicle had so many breakdowns and cost overruns— and was based on such outdated war assumptions— that Secretary of Defense Robert Gates terminated it this month for a savings of $14.4 billion. This was after the project had eaten $3.3 billion, driving the cost per vehicle from $5 million to $17 million, with prototypes still stumbling through tests.
Mr. Gates, of course, instantly ran into the new Republican chairman of the House Armed Services Committee, Howard McKeon, who believes that defense spending is much too sacrosanct to be included in the full-scale slashing Republicans promise for the rest of federal discretionary spending. Hold off “precipitous action,” Republican appropriators advised the defense secretary as they began hearings into the EFV and other worthy chunks of the $78 billion in savings Mr. Gates aims to effect across the next five years.
For the immediate moment, the secretary is rightly urging Congress to approve this year’s overdue Pentagon budget and put aside complaints about future cuts. “I have a crisis on my doorstep,” Mr. Gates warned about current military readiness.
The Pentagon budget has doubled in the past decade and now represents more than 50 percent of discretionary federal spending, and that doesn’t include the cost of two wars. How can it be off limits? If Congress tries to revive the wasteful EFV project, the secretary warns its ballooning price tag will swallow most of the Marine Corps’ future procurement and maintenance budget across the coming years.
The EFV is a classic in the excesses of the military-industrial complex, with entrenched politicians promoting hometown pork and reeling in political contributions from weapons developers. Republicans are particularly devoted, but this is a bipartisan way of life. Among the Tea Party House freshmen— sworn to root out waste— only one has dared to say “everything needs to be on the table”.
The EFV opens as exhibit A in Congress’s knee-jerk commitment to bottomless defense spending. Original plans were for 1,025 vehicles, but that was cut to 573 as prototypes failed. Invoking national security and Marine Corps glory, appropriators now are suggesting that the nation could afford at least 200, right? The nation needs responsible lawmakers, not salesmen intent on protecting an assembly line for lemons.

Rico says this will all be replaced by Howe & Howe's incredible (and way cheaper) Riptide: