I'd been trying to figure out why they required a user interaction for some of these. 5 out of 6 of these can be explained by debouncing.

• "Wi-Fi" and "Bluetooth" connection triggers are extremely susceptible to bouncing on and off with variable radio conditions

• "Arrive", "Leave", and "Before I Leave" are all susceptible to bouncing in and out; they combine a fuzzy location of variable precision with a point and radius

By requiring a user interaction, it makes sure that bouncing never causes the shortcut to trigger more often than desired. Apple certainly tries to debounce the event automatically, but that comes with other side effects: the trigger can be delayed significantly and unpredictably.

(As for why "Time of Day" requires a user interaction, I have yet to hear a satisfying explanation. I want my Cron!)