Well, look at it differently, this razor-style blade will get the job done quicker & easier than using the typical butter or steak knife onboard most aircrafts these days to cut the seat belt open.
http://www.amazon.com/LifeHammer-Ori...=cm_cr_pr_pb_t

We've done it in training/extracation field exercises using webbings & seat belts - a few seesaw motion, back & forth will cut thru it. A new letter opener, unused, is best for keeping it handy & easily accessible as a cutter as the blade would not be dull/worn from other use - instead of spending money for something like this.
http://www.amazon.com/Orange-Public-...d=1373349815&s

The pilots/crews onboard Asiana 214 apparently had quick access to an axle (kept on the flight deck ??) that was reportingly used to deflat the escape chute that opened inside the cabin, trapping & pinning 2 FA's - but had no Swiss Army or Leatherman pocke knives/multi-tools until PD/First Responders arrived (and, we know that seconds counted & mattered.)

A high quality EMT Shears would also quickly cut open the seat belt in an emergency if it cannot be unbuckled - but. most of us don't walk around/carry them on trips (even if it's not taken by TSA these days) - I have one in the mobile first aid kit - along with a steel hammer & mini-rescue/crowbar (leather work gloves are a must for safety reasons.) http://www.brigadeqm.com/ProductDeta...uctCode=EMT750

Perhaps, and it's my sincere hope, that after this incident, that the US-based FA union/lobbying folks would re-visit their vocal opposition to TSA easing the ban on small pocket knives. According to at least one news report writen, 6 or more injuried pax/crew on OZ 214 had to be cut out of their seats with the belts still fastened as toxic smoke & fumes begin to spread throughout the cabin & the fire began to burn due to jet fuel spilled.

For anyone who prefer a higher grade - order this pro style 7" Rescue Hook - http://www.brigadeqm.com/ProductDeta...oductCode=BM07 (although I wouldn't count on TSA allowing it thru their security checkpoint) ...