PDF Password bypass problem

hello guys, then, the problem is this. I want to save a pdf and I want to make sure that it is only printable, that it cannot be opened or modified or "copy and paste". So, from the save panel I create a password and set that the file is only printable. And so far so good, so I can open it to be printed only in acrobat (any version), if I try to open it with any other program it asks me for the password, and this is correct. But if I open it with "preview" on Mac, he allows me without asking me for a password or anything, so I save it as another pdf and the newly created file has no protection, neither reading nor writing. This problem exists in both Photoshop and Illustrator and Indesign. And the best part is that I had other people, with other platforms, send me different files, all password protected, authorized only for printing. The result is or same, I can safely bypass the password.