This week, we spend most of our time talking about the systems in the game.
While I really dislike the Stealth Driving tutorial, when I was trying to come up with a better way to do it, I really couldn't. The mechanic isn't intuitive, so the game does need to walk you through it. Since the designers know that the player has to go through the story if they want to get farther, it makes sense to use on of the early story missions for that tutorial, so that's what they did.
And then, and this is speculation, I imagine that they realized during or after the development of this mission that it wasn't fun. Unfortunately, at that point there likely isn't much they could have done. If they removed the mission, then valuable development time and resources would have to be moved away from other parts of the game in order to focus them on creating another driving mission. Retooling what we have now would have also taken up those resources.
Removing it also wasn't an option. As horrible as this mission is, it does teach the player everything they need to know in order to evade the police. In the sense, it is necessary to have it included in the game.
So while it is awful, I can imagine a designer thinking that just leaving it as is would be the best of a bunch of really bad options. I would love to ask a member of the Watch_Dogs team about there time developing the game, just to better understand what was going on behind the scenes. There are a number of rumors, but it's hard to take them too seriously without confirmation from an inside source.