I love blind contests as it keeps my mind clear, and I can focus on my own work! Everyone's work can be copied, and altered no matter how good you think you are. You could be the best, and someone still ends up mimicking your designs with these public contests. Hello, these designers (just like you) are extremely talented---at least most of them are.
On the other hand if the CH is rude, and dishonest they will go ahead, and tell another designer to make their design like yours.
This happened to me before in a blind contest when the CH literally uploaded my design to another designer and said "copy this!" Luckily, on that design site it was against the rules so the designer's account was suspended, and the CH was forced to award me the prize as it was my concept and the contest was guaranteed.
Never worked with them again.
Blind contests are sometimes bittersweet, but for the most part I like avoiding copycats. If you are truly creative you do not need to copy someone else's design to win. Going in your own direction or off course can sometimes (or in my case most of the time) guarantee you the win!