It would be more accurately to say that all those who understand how encryption works (which excludes most people in managerial positions, even if they have the power to decide what kind of encryption is used in their companies) cannot trust any kind of encryption embedded in a hardware device whenever it has to be used for protecting really important data.

The reason is that all encryption is based on the separation of place between the encrypted data and the encryption key. Whoever can access the encrypted data must not have any way to access the encryption key.

Whenever you give your encryption key to a hardware device, or worse, when the hardware device also generates itself the encryption key, it becomes impossible to ensure that the attacker will not be able to access the encryption key.

It is impossible to know how the encryption keys are stored inside a hardware device and how and when they are erased and how easy or how difficult it will be in the future for an attacker to retrieve them.

It is impossible to believe any marketing claim of the vendor of a hardware encryption device about how tamper-resistant the device is, because such claims have very frequently been proven to be lies (even when the claims come from the largest companies, e.g. Microsoft and many others like it) and it is too difficult to distinguish truth from lies in such cases.

The only reliable means of encryption are in software, under complete end user control (or equivalently, in a custom FPGA).