Lighters are one of the few things it actually makes sense to restrict on planes, since they can be used to make flamethrowers (with any aerosol can) or to light fuses on explosive devices.

Now, if in exchange for banning lighters they ended their eternal fascination with small, pointy things (and I consider "small pointy things" to be anything smaller than a machete), I'd be okay with it. Not perfect but it would be a step forward from the paranoia that currently drives Fatherland Security.