I don't think people consider URL shortening as a security measure, more of a convenience measure. Also, you should bare in mind that many users of such service

I don't think people consider URL shortening as a security measure, more of a convenience measure. Also, you should bare in mind that many users of such services are not exactly technically savvy (especially compared to the HN crowd, which often gets forgotten here). Given that, if a company is providing URL shortening for their product (such as One Drive), that should be their responsibility to protect the users.