There was just too much shit in Rift that didnt make any sense. Rifts werent logical most of the time. Why would all types of Rifts be hitting the same area at the same time that are all warring with each other? The story of the zone would completely hint at one type of Rift and them being ever present at any turn. So where would the other Rifts come from? Why would they show up there? What exactly were they after? To capture the city? Some of the most lack luster city design I have ever seen, they wanted that?
The random aspect added something to "do" to break up the monotonous questing of Rift, but they never had a point. Instead of 40 players in zone = trigger zone wide rifts, why not as an individual player travels through the zone completing quests.. his actions would cause a rift to open. Then, as that "ONE" player completes the final quest in the zone, it spawns a zone wide event. Each player journeying along that quest triggering just a shit storm of Rift events, then as the zone came to a slow ebb and flow of players, the events did so as well. Then, as they were designing the quests, the jewel of their f'n game, RIFTS, would have been sewn into their quests. Not talked about in third person for 95% of the game.