Interrupting the Game Flow = Annoying as Hell

I just started playing Assassin's Creed, in which you play as Altair, an Assasin who is doing his Business around 1191 in Jerusalem and other middle eastern medieval cities. Unfortunately, Ubisoft almost ruined the game experience totally, as the first 20 Minutes are pure frustration. The game starts like many others: You got some sort of Intro, then a tutorial. All good until this point, but then the first mission starts and you are constantly interrupted. Walk three steps - bang, tutorial popup. Climb a ladder - bang, tutorial popup, explaining how to draw a weapon. Guys, making a stealth kill was covered in the tutorial 5 minutes ago! You then make 3 more steps and bang, cutscene. 2 more steps, cutscene. 4 steps, cutscene.

Where is the fun in that? I want to play the game, not being interrupted twice per minute! Cover the basics in the tutorial and then introduce new elements in a way where it does not interrupt the flow all the time. Luckily, this gets a bit better during the game (I first played it at a friend, so I can see how good this game really is), but it's the first impression that sells a product usually, and the first impression of Assasin's Creed was horrible so far, because there were no 10 Minutes of consecutive game play.

Assasin's Creed is not the only game guilty of this "Tutorialitis", it's just the latest example that I've played. I don't really understand why game developers are doing stuff like that. If you have a Tutorial, why does the first "real" mission need such popups all the time? Make the first mission easy enough to finish, but there is no need to explain stuff again that was explained 5 minutes ago, that's just interrupting the flow and fun.