I don't think you understood zeidrich's point in this case :) There's no tragedy of the commons for copyrights because the commons doesn't get reduced by usage. Tragedy of the commons as I understand it applies to things like air, which is free, but which people can deplete. (Externalizing pollution costs.)
Things like research can end up belonging to the commons but there's no tragedy of the commons argument about it. Instead your parent in this case I think was just pointing out that this is stuff that wouldn't exist at all if it weren't commmercially protected.
While you are technically correct that tragedy of the commons only applies to nonexcludable-rival public goods, your pedantry has helped nobody in this comment thread learn more. There's a time for it, and most pedants fail to see when it is actually important to correct definitions.
Not according to the article I linked, which even has a four-paragraph section called "metaphoric meaning" that does not extend to that meaning; nor do any of the examples in the long list of examples under the section "modern commons" show such a meaning.
The term "tragedy of the commons" simply refers to a different concept. It's just not what it means. It means common resources become less useful over time.
This is not a statement about investment; it's just that the effect that is described is quite specific. You don't have to use an incorrect term to describe what you're talking about.
Things like research can end up belonging to the commons but there's no tragedy of the commons argument about it. Instead your parent in this case I think was just pointing out that this is stuff that wouldn't exist at all if it weren't commmercially protected.