I can see how it might feel that way, but consider the scale of the business we're talking about and the added logistics, time, and ultimately costs that would be incurred if it were done that way. There would be a lot more mistakes on the assembly line if vehicles were produced in the random order that they were requested, instead of organized into logical productions runs with common features. There would need to be a lot more car haulers taking much smaller payloads, because the odds of a batch of consecutive orders going to the same place would be incredibly low. If a defect were found in final quality control, the gap in the line would throw everything off. If a customer didn't fill out their profile, the rest of the world would have to wait until they could be reached. If a customer rejected a car because of a minor paint scuff that was buffed out in 30 seconds, it would have to be shipped across the country to be delivered to the next person who ordered that exact spec, instead of just delivered to someone locally who ordered the same spec a few days later. Obviously these are all extreme examples, but think of all of the limitations to getting hundreds of cars per day delivered, then consider how much harder it would be if everything had to be kept in nearly the exact order that it was submitted.
Even in a case where someone had the same order date, same delivery location, same specs, their time to completion of their profile can affect their order priority. If one person applied for Tesla Financing and the other took three business days to get approved by their credit union, that's enough to make a big difference in VIN assignment. I specifically asked my SA if there is anything I can do to ensure the fastest delivery, and that was his #1 suggestion, get the profile completed in full immediately. He also said more options gets slightly higher priority. Unfortunately it was a holiday weekend, so I couldn't apply for financing until Tuesday. Even though I was approved instantly, that probably put me behind many people who were fine with Tesla's rates, or were paying cash and linked their bank account showing that the funds were available. I don't feel disrespected, it's just business.