Please gt, there is no way science is going to stand in the way of exploitation of Mars.
It already has, with the debacle about Curiosities drill that didn't get re-sterilized properly. Under the mission rules they can't allow the rover to get near water for fear of causing a contamination from Earth bacteria.
Finding life won't stop the exploitation of Mars, but it will throw up some major road blocks to human presence as scientists insist on a heck of a lot more remote sampling of the indigenous life before they dare risk contaminating any of it. The number of unmanned missions will go way, way up, as will the requirements of manned-mission sterilization.