That is so bad on so many levels -- you destroy any raster content, like type, and you should never paste from Photoshop because you only get the screen preview.
So what happens when you try to place a PDF?
I get the message that I can't place the PDF. I need a work-around.
Show options when placing and make appropriate selections.
What Bob said. It's usually a bad choice for Crop option left over from the last time you placed an Illustrator file.