First there is the problem of what you do if someone gets access to your script. But that is minor.

Much more serious is the fact that one time pads only work if you only use them once. Suppose someone gets access to your data. If they xor an "encrypted" password with the real password, they get your xor data back. All they need to do is take a small dictionary of common passwords, xor it against 100 passwords, and look for some piece of xor text popping up more than once. (Lots of people use very bad passwords.) Once they find that, they now have your xor text and they have everyone's xor text.

If you are doing this anywhere, be assured that any serious security audit should find the fact that you are doing this, and you will get a lecture about how wrong you are.