there are some morons about unfortunately, yes you Ted
the fan doesn't blow out the gas flame because the fan's not powerful enough to do so and its situated well above the gas burner. the purpose of the fan is to provide a more even spread of heat within the oven.
it really comes down to personal choice, i dont like electric ovens because to me the food tastes different for some reason.
also note that if you have an electric oven/gas hob you may require an electrician to install a fused spur to feed the oven which means you need 2 tradesmen rather than just a gas fitter if you went for all gas.