A Civilian, some of the things you say about Churchill are undoubtably true, but at the time of his assuming the premiership was there a better candidate ?
The foreign secretary, Halifax, was favoured but he was a defeatist and an appeaser who actively conspired to make peace with Hitler. If he had achieved his aims you can bet your bottom dollar that it would have been on Hitler's terms.
Even after Churchill's "we shall never surrender" speech, Halifax, aided by others in the FO, was indicating to the Germans that peace proposals would be made.
The world would be a very different place if Churchill had not taken the reins of power because, as In Fin put it, he provided leadership when it was so desperately needed.