The goal is throughput. They want to maximize their ridership on their most popular rides, and empty seats decrement their cumulative capacity. Ergo, single rider lines are utilized intended to fill those single seats. It is literally that simple. Disney (or Universal, or Busch Gardens, or whoever) does not care who is in that line. They just want to fill spots to maximize total riders and efficient usage of the attraction.
My son uses it, and we may use it this fall if needed, exactly as the OP discussed. It is neither rude nor unethical to use it, as long as you fill a single rider vacancy. I would never dream of asking someone to try to seat me with someone I'm in the line with, as that completely defeats the purpose of the line. Nor do I mind 50 people getting in that line in front of me as a group, and riding one after the other. The single rider line isn't a perk or an exclusive use. It is not a promise or a benefit. It exists to help Disney CMs fill busy rides, and concurrently provides win-wins for park attendees willing to split their rides up with POTENTIALLY shorter waits.
I'm probably the 30th person in this thread to make that point, but there it is.
My son uses it, and we may use it this fall if needed, exactly as the OP discussed. It is neither rude nor unethical to use it, as long as you fill a single rider vacancy. I would never dream of asking someone to try to seat me with someone I'm in the line with, as that completely defeats the purpose of the line. Nor do I mind 50 people getting in that line in front of me as a group, and riding one after the other. The single rider line isn't a perk or an exclusive use. It is not a promise or a benefit. It exists to help Disney CMs fill busy rides, and concurrently provides win-wins for park attendees willing to split their rides up with POTENTIALLY shorter waits.
I'm probably the 30th person in this thread to make that point, but there it is.