I didn't say the GTA games were bad, I just said that Assassin's Creed was no more repetitive than a GTA game. If you think about it, both games feature large open-world environments to explore, as well as story-based and side missions. Because of the sheer magnitude of the game world, some of the missions invariably involve doing the same thing, albeit in different areas or with different opponents.
It's always drive somewhere quickly, or kill everyone at a specific location, or escape from the cops. How is that any different than eavesdropping on coversations, or picking pockets, or escaping pursuing guards? My point is that there are only so many mission variations with the only real difference being the environment in which you do them.
Some find that kind of thing repetitve, but I don't. As I said, I enjoyed Assassin's Creed immensely, so when I'm comparing it to GTA, I'm doing so favourably.