When I am critical I do try to point out that they are as a rule as far from keeping the Torah as one could expect from hypocrites that put on religious clothing and make money from doing so.
I can imagine there are out there religious teachers that sincerely think they are keeping the Torah, but I can reassure them that they are not. They are obstacles keeping people from Torah. It all begins with their using the Torah to make money. After that it is all downhill.
I do not think that they will ever change. So the only point of this is to warn others about the danger in these people, especially for innocent people that really do want to keep Torah. If you want to keep Torah, the last person you want to be talk with is a religious teacher.
A positive suggestion would be to learn Torah yourself. And if you can find a place that learns and teaches authentic Torah--that is the Oral and Written Law with no additions masquerading as Torah, then it is a good idea to learn there. But such places are rare. And most have lost the authenticity. Now they are career orientated. That is they generally are out to make more the religious teachers. May God save us from them. I wish I did not have to mention this negative aspect. I would rather focus on the positive side of Torah. But I still have an obligation from time to time to mention this important point to warn people.
[I should mention the distinction is simple. There are people in legitimate yeshivas who are sincerely interested in learning and and keeping Torah. And sometimes it happens by mistake they get the name "religious teacher" attached to them. This is confusing. But as a rule yeshiva people are not the kind of monsters that I am referring to here. So this distinction is important to keep in mind. People in straight, Lithuanian yeshivas are not the kind I am referring to here.
מפסמים את החנפים בשבל חילול השם. The Talmud tells us we are required to shout out the name of the hypocrites to make sure people know about this problem. And the Chafetz Chaim goes into detail about this in chapter 7 of volume I. He makes clear there there are times when one is obligated to say Lashon HaRa, and concerning religious teachers this certainly applies. [In that chapter he deals with the issue of when we are required to warn people. That is not to only place, but it is the one I remember off hand.]
I thought about deleting this essay, but for now I will leave it. It brings out an important point. That is that anyone who really cares about Torah, should to get rid of all religious teachers. The only institution that really deserves support are authentic Litvak [Lithuanian] yeshivas where real Torah is learned.
The question is how to get rid of religious teachers? This is highly individual. People have to realize on their own how bad they really are. There is nothing I can say until people discover this on their own. And by then it is too late.
The dividing line is not exact. You have supposedly Lithuanian yeshivas that are cults. On the other hand Breslov which tends to be problematic, still has plenty of people that are sincere and from the Side of Holiness. In fact, outside of the leaders which everyone knows are crazy, the majority of Breslov are in fact simple, sincere Jews.
So what is the dividing line? How does one tell? It is hard to know. Rav Shach certainly was able to see the difference, but besides him I have not heard of anyone. On the outside appearance there is no difference. The Dark Side is even more strict in rituals in order to make itself seem kosher.
The word "religious teacher" is not in itself a proof of evil. After the new kind of ordination started by Rav Joseph HaLevi from Vienna people started using this term. But still you have great people that were refereed to as "Rabbi." No one says "Rav Akiva Eiger." It is "Rabbi Akiva Eiger".
So the main indication is probably simply affiliation with the group the Gra put into excommunication. That seems to be the basic dividing line. The fact that that Gra was ignored in this point is how everything went downhill.