Perfect answer. This is exactly the case, from Swanson's seminal text mining in biology paper on fish oil in the 80's with Arrow, to modern tools like Leach's Hanalyzer: You need to focus on a very narrow target application or have a clear hypothesis you wish to prove. And, wetlab work, human intervention, and tons of labor are major ingredients of those (rare) examples that go beyond information retrieval or very targeted information extraction. (Also note how none of these guys was able to scale that work and produce a whole chain of findings... ;-))