';Registered Mail';, then clear tape not allowed by USPS, WHY?

I have recently packed a letter nicely and used some clear tape to secure the envelope, but the US postal Services removed the tape actually causing the envelope to be damaged and then they put the brown tape that I feel was not secured, but the post office person told me that I I want Registered mail then I can not have Clear tape. Why USPS has such rule?';Registered Mail';, then clear tape not allowed by USPS, WHY?
For security purposed the tape used to secure registered mail must be clearly visible so if the package is tampered with it will be evident.





The born tape is actually much more adhesive than clear. Removing brown tape will permanently damage the envelope.