The interior of the Tower of Nightmares has periodic group events. These collect players into groups, which is necessary because trying to run through solo is nigh unto suicide.
There is a group event at the entrance. This groups up people like in the tutorial. The event ends, and a small zerg descends upon the maze. Halfway through, a champion awaits, and dispersed players unite to defeat it. Thus gathered, they proceed to the second section, now able to safely proceed as a group rather than dying in a thin line. And so on.
This is good design. It organically groups people without their even noticing it’s happening. It promotes and rewards doing the right thing to succeed.
We led a guild group through the tower a few times to help people unlock the travel points. I had a chant of “If you run ahead, you will die alone. Don’t stop to rez those people or you will die too.” We would built up a large enough group behind us to stop and rez the people who still charged ahead into the mass of death.