I really don't see how its a knock against Stiles that she was acclaimed. To me its a very positive thing when someone is viewed within their party as being so talented and such a consensus choice for leader that no one else runs. She was acclaimed because she is that good. Other parties should be so lucky as to have a leader who everyne agrees from the get-go is the best person for the job!
In fact in Canadian political history almost every single time that a party has a chosen a leader by acclamation - that person has won the next election (e.g., Danny Williams, Brad Wall, Dave Barrett, Mike Harcourt, John Horgan, Roy Romanow...).
... Michael Ignatieff ...