Agreed, and before terminating an account above some threshold size (say top 5%) there should be a human review or confirmation. But this is not surprising or even unexpected behaviour from YouTube. There are loads of horror stories from users who get their account shut down for 'minor' or accidental infractions. If a user is going to rely on a service with a history of unsympathetic and unpredictable enforcement then they should always take the most cautious approach when uploading.