Yeah, reading anti-Mormon material is frowned upon. But of all the anti-Mormon material I've read, very little of it shines light on things that I hadn't already heard. Most of it is jumbled nonsense and the ramblings of people who feel hurt and betrayed.

It's better to get things from the source

Pretty true. It's funny reading the ExMo sub and seeing people talking about how they 'deconverted' their family, or how they wanted to know more about the church so they went on that sub. Clearly they're lying for internet points. If you want to learn about something, you use multiple sources. But going to the source that opposes the thing you're learning about with every fiber of its being, and using only that source, is really stupid.