Code signing doesn't stop redistribution of unmodified copies of software, and it allows for cryptographic attestation of its origin (when used properly). If you modify the software, you'll have to re-sign it and make sure your code's consumers trust that signature's chain of trust.
DRM prevents you from redistributing original media (with varying degrees of effectiveness) and doesn't do much for cryptographic attestation (nominally).
These are two very different systems for different purposes.
In what way does code signing prevent you from using your computer as you want?
As far as I know you can run unsigned code pretty easily still (especially, though not uniquely, as a technical user), and the process of stripping attestation/signing information from an executable on most popular platforms is well-documented with freely-available tools in most cases.
I'm almost certain there are ways to disable code signature checking completely on the major OSes if you really want to, but why you'd want to do that, I don't get.
Is your argument that running code with an invalid signature should happen with no notice, no hurdles, no nothing, by default?
I cannot place a file in my profile directory and have firefox execute it without having it approved by mozilla. I booted my old PC to check on something recently, opened firefox by opening an html file, and discovered that it had disabled all my extensions making it less secure by allowing every webpage to do RCE had I changed tabs.
Then there is secure boot which requires MSFT permission to use an OS, cell phones on which you cannot run your own code without manufacturer permission.
I hope you don't still think the R in DRM stands for rights.
When using the Debian builds of Firefox at least, you can just symlink the extension directory into the system Firefox extensions directory, even if the extension is in your home directory somewhere.
