You have left out the second half of the sentence, "... by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries."
The position taken by the courts and the administration is that "authors and inventors" means "human". The monkey could not be the author of its own selfie photograph, for instance.
Maybe this doesn't reflect the intentions of the Framers, but it certainly should color any modern discussion surrounding the purpose of copyright law.
I also notice it doesn't say anything about their heirs. I wonder if there is a meaningful argument that copyright extending beyond the life of the original author is unconstitutional.
Likewise corporations are not humans, so they shouldn't be able to own copyrights either.
Are you just arguing that corporations should not be able to own copyrights but it is OK for them to own other things such as land and equipment, or are you arguing that corporations should not be allowed to own anything?
"Intellectual Property" is not, or at least should not, be the same as physical property. Copyrights and patents are temporary artificial, government enforced monopolies to incentivise creativity and publication of the results of that creativity. I don't think it's unreasonable to say that a corporation can't own the copyright itself. Although, they should still be able to hold a license to works from the actual human creators, and granting such a license could be a condition of employment (provided it was created as part of the employment, and not, say, on the employees own time).