I think it comes down to this:
If you believe that the official line for 7D is always at the ride, and that's immutable, and that the RD crowd is just a random group of people who happen to be heading that way, you'll believe that Disney has no right or rationale to stop people at BOG from heading directly to 7D as soon as the rope drops.
If you believe that Disney can say that prior to RD, the line for 7D forms at the rope at the main gate, and that's the official line for the ride, and at RD, a CM will relocate the line to the ride, then you'll believe that it's reasonable for Disney to say that if you want to ride 7D at opening, you need to be at the main gate before RD to join the official, movable line.
Some people disagree with Disney choosing to take the second approach, and that's fine - people have a right to various opinions. Some people simply don't understand how the second approach could possibly be valid, but I don't know what else can be said on that. Some people think they have some sort of inherent right, regardless of any crazy line organization Disney might choose, but no, in the absence of any clearly false advertising, it's Disney's parks, Disney's rules.