The citizen's role in itself is already a challenge. As seemingly powerless and helpless you are, you just might be able to change the flow of the game, and that's the challenge. However, I can see where the citizen-dislike is coming from, as I also don't tend to enjoy playing as a citizen.

I read most of the arguments defending citizens here but I think that you guys are forgetting something : This is about replacing a citizen role with another powerrole, not completely remove an entire player from the game. Take this example.

Game setup for townies :
1 sheriff, 1 invest, 1 consort, 1 doc, 1 random town

Now let's say that you happen to be the citizen from the random town. Yeah, you can do all those things that you guys mentioned in your previous posts, deceive other mafias, speak out loudly without concern, take attention away from the powerroles and all the other awesome stuff he can do. But then, did you ever consider :

What if we excluded citizen roles from random town? Now you'll have obtained a powerrole! Woo. Now then. What stops you from doing all the stuff citizens do (except the vest. But don't go around arguing about how awesome the vest is, because the survivor normally has 2, and because of that, the survivor > citizen, especially with the fact that he has easier winning conditions, which is much more fun because you can immediately change sides to whoever is winning) ? Not only have you obtained a useful role (Either checking other peoples roles, healing other people, role blocking and whatnot), but you can still go around parading.

In the first scenario, there're only 3 powerroles and 1 citizen. In the second, there're 4 powerroles. You can do what citizens normally do and still get the benefit of a powerrole.