Probably because the number of detection will be too few to test old theories or make new theories with the experimental results.
Physicists love to be wrong! If there is an experiment that disagree with the current theory, then is like the will west and everyone can publish their own pet theory that "fix" it. It's like raining free paper for them, their graduate students and everyone. Also, it's fun!
When experiments and theory agree, they have to use imagination to get a new "interesting" tweak that can be published. In some case the the tweak may be interesting, but most of the times it's not.
I remember a talk about a 2-sigma "particle". There was a small disagreement in some experiment, so someone did a thesis about a possible fix adding a new particle. A lot of hard work and hard calculations. It was a nice talk, and someone asked what what happened then. The sad new was that later the 2-sigma disappeared, it was only a fluke :( . This kind of work is important, but it's more boring that looking for new particles.
