Of course. Nobody is arguing that they should be deprived of exclusive rights. The argument is if it is legal to modify an item after it is legally purchased.
Um, because you made that up? If I steal your car and leave a check for its market value, was there no crime? I'm flabbergasted that you can make this argument with (as far as ASCII can tell) a straight face.
Incredibly bad example of a strawman argument.
The question is what has been legally purchased. Intellectual property is not an instinctively easy concept. If I buy a DVD, I can treat that disc in any way I see fit. I can toss it in the microwave, throw it as a Frisbee in the park, glue cork to the bottom and use it as a coaster, or load it into a skeet launcher and fire a 12-gauge at it.
No one is arguing that it should be illegal to skip scenes or mute dirty words on a DVD. I have every right, as the buyer of a book, to skip over page 212.
But if you sell or distribute the movie without those scenes, if you sell your version of the book with page 212 ripped out, you are selling something that does not belong to you. You are stealing the fruits of someone else's labor and twisting someone else's efforts to your ends.