No wonder. Was one of Churchill's flubs.
https://legionmagazine.com/dieppe-they-didnt-have-to-die/
When writing his epic multivolume history of the Second World War, Winston Churchill had to discuss what he called the very controversial Dieppe raid of Aug. 19, 1942. To those who were assisting him in his research he wrote, it would appear to a layman very much out of accord with the accepted principles of war to attack the strongly fortified town front without first securing the cliffs on either side, and to use our tanks in frontal assault off the beaches.
Layman or not, Churchill, of course, was precisely correct. But in the end, after strong protests from Admiral Lord Louis Mountbatten, the architect of the raid, Churchills published account omitted almost all criticism. In fact, as we now knowthanks to a careful study by the British historian David ReynoldsMountbatten was allowed to rewrite the draft to make it almost totally self-serving. Churchill had his share of blame for the disaster too. Reynolds notes sharply that Mountbatten, this egregious political climber, had been absurdly overpromoted by none other than the prime minister. No hands were clean in 1942 and Dieppe still besmirches reputationsexcept those of the soldiers, sailors and airmen who had the bad luck to be on, off and above the stony beaches around the old French port town that summer day.
The reasons for the raid made sense. In the summer of 1942, the Allies were losing the war. The Japanese had been checked, not stopped, at the great naval battle in the Coral Sea, Field Marshal Erwin Rommels Afrika Korps was ensconced deep in Egypt, and the Red Army was in retreat once more as the panzers surged eastward toward Stalingrad. The Allies had no victories to their credit, and the pressure from Moscow for a second front was intense. So too, was the American Chief of Staffs desire for a small, limited-objective invasion of France. Churchill knew this would be a mistake. Without air superiority, without specialized landing craft, without more and better trained troops, a second front could only be a disaster. But a large raid on France, on Dieppe, might ease the pressure on Britains leader by doing something.
Planning the raid on Dieppe, a reconnaissance in force, was initially a British show, bringing Lieutenant-General Bernard Montgomery, commanding in the southeast of England, together with Mountbatten, the Chief of Combined Operations. But when word of the planning leaked out and came to Lieutenant-General H.D.G. Crerars attention, he demanded that Canadian troops mount the raid.