MW
I do agree that people that re doing things wrong should be noitfied. It is all too common that people hold from various rabonim and various personal issues that can have an impact on what they are doing. I am not saying that eating treif should be muttar but the person rushing in to criticize and point out flaws on other people should first be sure that they are in a position to give mussar. Once you are assured that you are in the position to give mussar then you will have to weigh the fact that perhaps the person who is “not following halacha” is either following the psak of another rov that is matir whatever he/she is doing or perhaps it is assur but he/she were goven a heter for various reasons.
That said, I disagree with you on telling people what you belive they are doing wrong. I persoanlly get upset when someone points out something that I am doing that is not correct. It does not draw anyone closer to frumkeit.