Except that generating and delivering an equivalent amount of heat as electricity is an order of magnitude less efficient than burning the natural gas directly to heat your food or water. No matter what mumbo-jumbo they're spouting, you still need to expend a certain amount of kilocalories to heat a galllon of water or to cook a dozen eggs.
Except that the pots and pans we use are horribly inefficient. You only have to hold your hand above the edge of pan on a gas cooker to realise that an awful lot of very hot air is rushing past the pan and not having its heat extracted from it. A while back I saw some pans that, unsurprisingly, had a bottom and sides that looked very heatsink like which improved the efficiency of the pan by at least a factor of two.
On the other hand it's hard to believe that the inefficiencies and losses involved in electricity are not going to be bested by a well designed water heater. Both burn gas in the first place, the thermal efficiency of heat transfer to water is probably going to be similar in both cases, but electricity then has generation and transmission losses to cope with. Obviously there are some indirect transmission inefficiencies in distributing gas too, pumping the stuff uses significant energy (There are 520 MW worth of gas turbines just used to pressurise the UK national gas core pipelines, before you consider what's used for local distribution). For heating hot water both methods could of course be greatly improved by using the energy not to heat the water directly, but to drive a heat pump to heat the water - even if you only get a CoP of 2 that's a huge efficiency gain..
Yeah, but the duty cycle of a gas hob does makes that a pretty small concession to reality; you spend much less time heating than any other way besides inductive. There your switching efficiency probably beats a resistive coil, might begin to approach break-even... but I doubt it.
Under any circumstances, cooking over gas is much more viscerally pleasing... while a ceramic cooktop (even the new halogen ones) is much easier to keep clean, there are some things I feel we have a right to keep as they are. Some people grill over wood or charcoal for the same reason; I prefer a nice old propane BBQ with lots of dripping-cinders on the vaporizers.
With grates scrubbed clean every use, of course.
mnem