They literally cannot start with freelance missions. You are forced to do regular missions first. Hence, they are denied access. Further, in freelance, one might not want to do flightseeing or cargo missions, and you do have to do those first before doing later mission types. I understand that technically you can do missions for like 700 hours and gather millions of credits that way, but the reality is, you are forced to do flightseeing and light cargo in freelance, effectively denying access to flights they want to do.
The entire issue stems from the level of control they want to exert over a single player experience. There is no reason not to let people play how they want to. It does not affect anyone else at all. Someone skipping to flights they want to do, does not affect your experience at all if you don’t want to do that.
The only reason to control a single player experience like this and make it online and control it, is money. 100% money. This pattern has played out a million times in AAA gaming. If they offload this to client side only, I will then back down from my belief. Until then, they are going to sell stuff, mark my words.