There are technical limitations. Think about going to the tower. There are only about 16 people in your instance at a time. Someone being in your instance is currently the only way to interact with that player (to see gear, invite to a group, etc). Connecting players on a larger scale requires connecting those players at a higher level, such as PSN or XBL. The only way a kiosk at the tower would work is if it used the PS4 or XB1 web browser to connect players, and as you can imagine, that would be an awful experience. I imagine Destiny 2 will have a much more robust matchmaking system.