Agreed, including fro other people's personal use.
Companies should be allowed to protect data by copyright or DRM, but not both, i.e. encasing something in DRM would remove its copyright.
If one uses technical means to protect information, parent poster proposes that courts should decline to protect it under the copyrights regime as well. Certainly, they should not protect both the information and whatever technical device is used to do private enforcement.
You can either use the public protection regime, or your own private protection device, but not both.
The issue at hand is that copyright implicitly includes an agreement to allow the work to pass into public domain after the copyright term expires. Technology that prevents that is anathema to the agreement. At the least, such schemes should fail-open, such that archived copies may be read as plaintext when the copyright term expires.
DRM is frequently used not just to protect copyright, but to also completely control access beyond the purpose of copyright. See the recent Denuvo snafu for an example of this being done (presumably) by accident, noting that it can also be done on purpose to e.g. plan obsoletion. It doesn't just control copyright, it controls your actual rights to access content you legally own and hinges that access on running a service in perpetuity, which is not the least bit realistic. It's digital rights management but treats those rights like a privilege instead.
A simmiliar model could be applied to copyright, in exchange for legal protections, you must forgo technical protections.