No. That's an individualistic logic. A democratic logic insists that you're a citizen and not an individual, and that requires that you do certain things that supersede choice.
Well put. It's not the same as voting for something like who should be evicted on Big Brother, we're all affected by the outcome of a GE and so we should all take responsibility for our futures. And whilst the OP probably had in mind those who died in WW2 when he talked about 'ultimate sacrifice' frankly they get remembered enough. The unsung, unremembered heroes are all those who fought the British Establishment for the extension of the franchise so that all men and women could vote regardless of position or privilege.
(And we all know that after last year's Brexit vote the British Establishment are deeply regretting that!)