On the one hand, as DY pointed out, we don’t know exactly what she said, so I can’t comment on her specific comments.
However, I do think that she is right for pointing out the problems inherent with the CR as well as most “Frum” newspapers, magazines, and websites.
I do think that there are a lot of negative aspects to the CR, and as your seminary teacher she has an obligation to point these out to you.
I don’t think that the CR is the ideal place for a person to be whether it’s for halachic discussions or socialization or whatever. However, we don’t live in an ideal world, and for many people, this may be the best alternative for them for right now. I do think that for me, it has been a lifesaver in certain ways, and I think that is true for some of the other posters as well (perhaps in the same ways; perhaps in others).
In terms of halachic questions, this is not the best place for them. However, I think that most of the people who ask halachic questions here are doing so because they don’t necessarily have a better option. I have mentioned in the past that although at times, I will mention that the person asking the sheilah should really ask a Rav, at the same time, I am sometimes hesitant to say that since the person asking probably does NOT have a qualified Rav to ask.
Also, I am afraid that the Rav they choose may be problematic. There are many people around with the title Rav and the fact that someone has that title does not necessarily make them qualified to ask sheilahs too. So if I know that I know the answer to the question, I do think it makes sense for me to answer it.
I do hope that most people realize that they can’t just trust anyone. And I hope that anyone who has the resources to do so doesn’t just rely on any “psakim” from the CR, and just uses it as a resource to be aware of potential halachic issues and solutions and sources. But the truth is, the idea of “not just trusting anyone” also applies to people IRL even if they bear the title Rabbi and have real names.
Unfortunately, nowadays, this is a tremendous problem – there are many “Rabbanim” and “poskim” (as well as “Rabbits” and “poskot”) who have a lot of hashkafic problems and are running around giving incorrect piskei halacha. Honestly, the average CR poster who answers halachic question may very well be more qualified than many of the “Rabbis” I hear quoted in real life.
Bottom Line: The CR is not the ideal place in general and certainly not for piskei halacha. Most people who are here are probably here because it is the best choice for them right now. As your seminary teacher, she has an obligation to guide you to the best places and steer you away from any that are less than ideal. Right now, while you are in seminary, you do have the best resources (in all areas- social, halacha, hashkafa, etc.) at your fingertips, so you probably should not need the CR.