You are confusing a "copy" (illegal for copyrighted works) with a "clone" (which often skirts the bounds of legality). Copyright doesn't save us from knock-off

You are confusing a "copy" (illegal for copyrighted works) with a "clone" (which often skirts the bounds of legality). Copyright doesn't save us from knock-offs. The hundreds of "Revengers: Age of Boltron" DVDs in the bargain bin at Walmart is testament to that. Those are legal. What copyright prevents is Cinemark buying a copy of Age of Ultron for $20 and then making hundreds of copies and charging ten bucks a seat to watch them in hundreds of theaters nationwide, never sending Marvel Studios another penny beyond that initial $20. Helping consumers avoid knock-offs is what trademarks are for.