Zarek treated the Godsfall Tears like a training exercise—to well and truly push himself to his limits.
In the future, it was actually quite difficult to find Godsfall Tears at your level, so it was rare to have the benefit of speed-running so many, even if he didn't care for most of their rewards.
Usually, Godsfall Tears would end up falling into the territories of one of the major powers or a powerful Turned. At that point, just making it there might be as difficult as clearing the Tear itself—and by then, you might not have the energy left to actually make it out.
Something like this, where you could clear so many at once, was only possible when you had, well… a power backing you. But even then, Godsfall Tears in this quantity didn't happen all the time. You had to wait for a Crimson Rain to descend.
Marx's offer this time was exactly what Zarek needed. Since he had failed to reach D Class that night, this would be his best chance to do so.