Again, I'd have you read Manchester's account of the debacle. Manchester deemed Churchill's original plan a brilliant idea went afoul due to the stupidity of the people over Churchill.
I'll repeat.... Churchill really wasn't in total charge of the whole operation. His main plan was supposed to be a huge naval assault on Istanbul. He never wanted trench warfare which began too late to be of any good. His plans were always shot down by various army or navy people who didn't want any glory going to Churchill.
So instead of a timely naval expedition on Istanbul followed by an army invasion of a depleted city, you had army chiefs twiddling their thumbs for many weeks before discarding Churchill's naval expedition and beginning the failed army invasion on the lower peninsula while the Turks had built up their defenses.
Evil, criminal losers.