It’s not just that say we find wimps in the lab we need to have some sort of a model that would explain how they are or were produced in the universe and more importantly that they were produced in the correct ratio to be the single explanation for dark matter.

It’s quite possible that we will find WIMPs in a particle accelerator but then be stuck with the fact that at best they’ll only account for 3% of the dark matter we observe and then it’s again back to the drawing board.