That is the essence of research (laughing). We run 1000 experiments with negative results for every 1 experiment that makes a difference in the world. I know exactly what you mean. The current project I'm working on right now (genetically modified plant enzymes) has been going on for 5 years now. We have made a lot of progress and learned a lot but it has taken 5 years to get here. If I have a list of 300 factors, I have to test them all. 299 usually display lowered enzyme activity for every 1 that displays unchanged or increased activity. But we have to test them all ... or else, we would never know. In the end though, given time, it is inevitable that progress will be made.
With the dinosaur researches the same is true. If thousands of scientists work on it every day for 50 years and share data with each other, eventually, we will have something.