I was pointed to t-nation around 2004 by one of my professors for my kinesiology degree. She also pointed us to Dr Squat and a few other sources.
I've seen people complain that "all there articles are advertisements" - well first off all generalizations are false. But when biotest is a sister company, why would they push another companies products? When they have the studies and quality control of their products why would they advertise for another?
I've also seen complaints that the articles contradict eachother - one says always squat, one says never squat, yada yada yada. Well yeah, its the fitness industry. Some movements are contraindicated for some people. Some movements are better for certain goals than others.
I make a small effort to defend t-nation. not for my sake but for theirs - they truly dont know what what they are missing in discounting an entire resource. But it's just like anything else, you have to do your own reading and decide for your self.
maybe that's it - t-nation makes people do their own reading and doesnt just say "here's the magic progam and magic pill"
I've never seen a deadlift that looked like a dog taking a crap from a guy wearing a t-nation shirt. But i have seen it in bodybuilding.com shirts.