UPDATE: I got an email from Motorola with the subject line
"Motorola Solutions Welcomes You to Customer Hub!"
This comes after I found a login page somewhere on their site that allowed me to request an upgrade to a business account. Unfortunately, due to how difficult MSI's site is to navigate, I do not know how to navigate back to that page, otherwise I would post a link to it here.
So far, I was able to subscribe to various different radio software and add APX CPS to my cart on Motorola's online shop.
The "secret sauce" is you need to apply for a business account. In my case, I explained to them that I am a licensed amateur radio operator and an end user of their products. I explained that I needed software and firmware for my products. That evidently has worked.
Everyone is so quick to say "just make a Motorola account!" Well, it isn't that simple anymore. This information should be in the pinned thread.