I find it interesting that most muslim converts always state that if they were to judge Islam by its followers, they never would have converted. They actually read the Quran and and its teachings which made them decide to convert. Hence if they were closed minded and judged religion by its followers, they never wouldve converted. Most muslim born people take their religion for granted and probably dont understand it completely and follow blindly.
I do agree that the way a religious group conducts itself publicly will impact on other peoples judgement of that particular religion but any sane person knows in the end some people dont necessarily practice what they preach and would be foolish to brand a religion based on how others practice.
If a person was really interested they would read up on the religion before making such a judgement, regardless of what religion it is. It is only then that they can make a proper judgement of a religion and can decide if it they think its good or bad. To me the people who are judging the religion by its followers are no better than the people who are claiming to be religious without really understanding the religion itself.