Why can I not have my membership tracked via an anonymous account?
Because FEDs and movie studio lawyers would use anonymous accounts. All of these requirements exist for one reason, to protect the site and it’s users. If you want anonymous then you should stick to public trackers.
The barrier to entry into private trackers is high enough that it’s not worth it. Soon after they started sending DMCA letters the admins would be alerted and it would take about 5 minutes to identify the preparator and ban them, and whoever invited them, and their whole invite tree. People complain about it being difficult to join private trackers, but it’s really a security feature.