I feel like you're getting into No True Scotsman territory here, especially since you're providing examples that have zero relevance to the matter at hand. However, I'll tackle your rebuttals in order:
- I don't think you actually understand the nuances of filing separately vs. jointly. It's a lot more complicated than just different tax brackets and "essentially everything else is the same". For example, filing jointly you cannot take the credit for child and dependent care expenses, you cannot take the earned income credit, you cannot take education credits or deduct student loan interest, etc. There are many more differences as well. It is, in fact, a separate code, not just a separate bracket.
- Individuals under the age of 15 also cannot get a drivers license. Does that mean they are not people?
- Obtaining loans has no bearing at all on legal status. But even so, a corporation can get all kinds of loans. What difference does it make if the loans are for capital or education?
- As you point out, women also are not expected to register for the draft, are they not people?
- The 5th amendment is a very interesting case with respect to corporations. You're kind of getting at the Collective Entity Rule, which basically says that an agent acting on behalf of a corporation cannot always exercise his or her personal rights, such as the 5th amendment. Here's what the courts had to say about the justification for the current state of affairs, "The privilege is limited to its historic function of protecting only the natural individual from compulsory incrimination through his own testimony or personal records" (emphasis mine). Note that it says nothing about "person". Also note that there is quite a bit of activity on this particular point, and in the near future the 5th amendment might be allowed to apply to corporations as well [1].
- Minors cannot be sentenced to prison terms, either. Are they not people?
- More limited does not mean non-existent.
No, I am not confused. In legal status, a corporation is a person. Period. The difference you're missing is that a corporation is an artificial person vs. a natural person (or if you prefer, a statutory person vs. a constitutional person). But still a person.
I'll also point you to the definition of Person from Black's law dictionary. Person. In general usage, a human being (i.e. natural person), though by statute term may include labor organizations, partnerships, associations, corporations, legal representatives, trustees, trustees in bankruptcy, or receivers.
[1] https://www.law360.com/articles/634828/high-court-may-take-o...