GMAT: What is the Point?

I understand that the GMAT is an indicator of “a person’s likelihood of success in a graduate business program” or whatever they tell people, but how? I have looked for the reasoning behind why this seemingly pointless exam is so important, and here is what I got from

1: Taking the GMAT exam alerts programs around the world that you are serious about your pursuit of a graduate management education, thereby increasing your likelihood of admission.

2: More than 5,900 graduate management programs around the world rely on the GMAT exam as the most reliable predictor of your success.

3: The GMAT exam is required for admission to many of the world’s top business schools.

4: Programs that require the GMAT attract the best students, which not only helps guarantee a rich educational environment, but also gives you access to an influential network of future business leaders that will enrich your career many times over.

I would like to comment on these four reasons listed on the website:

  1. Why wouldn't a strong undergraduate GPA, internships, extra curricular activities, great letters of recommendation and essay be enough of an indicator that someone who applies for graduate schools is serious? It's one other piece of the admissions puzzle; but being that it has nothing to do with anything business related besides testing a person's critical thinking/analytical mind (in ways unrelated to business), I don't get why it is so important.
  2. Okay? That doesn't tell me why it's important. It simply says that it is something business schools rely on... but WHY?
  3. Alright... Kind of just repeating reason #2 except it is pointing out the fact that top business schools look for GMAT scores. Again, WHY though?
  4. The programs attract the best students? Really? What evidence is there that proves that "fact?" I am pretty sure there are many intelligent students who may not have done well on the GMAT that deserve to be enrolled in a graduate program.

I am really not looking to be scolded here, so please leave negative comments aside. Those who can give me actual reasons as to why the GMAT is an important and necessary component of graduate admission: I welcome your responses.

FYI: I have not taken the GMAT and I do plan to do so. It is just frustrating to put so much energy into something that seems so pointless.

It’s a way to standardize applicants, because a 3.8 at Arizona State doesn’t equal a 3.8 at UVA. Also, business schools like it cause higher GMAT bumps their ranking.