I'm both tired of, and puzzled by, people in online games who seem shocked that I would report them for breaking a rule. I'm a believer in strict rule enforcement on the Internet. If you want to have a game or community without rules, that's great. But if the game or community has rules, they should be enforced very strictly or else they won't be taken seriously. That's just the nature of the Internet.
I almost always had a report ticket going in World of Warcraft and things will likely be similar in Guild Wars 2 unless that community is better. If I pay for an online game with certain rules, I want them to be enforced. If you aren't happy following the rules of a community or game, you can simply avoid it. No one is forcing you to be there.
The most common reaction you get from people is something like "omg ur pathetic" or "wtf snitches!!1!!one!!!" when you mention that you report people. I find it funny and, at the same time a great motivation to keep doing it.
So, in closing, if you don't want to follow the rules then fuck off. I will always report you and the more you complain about it, the more I enjoy doing it.