Any goal with "but don't kill everything" added is more complicated than the version without that stipulation (and that specific one only saves a single microbe). The simple goal is easier to accomplish, so free market competition guarantees we'll try it first. Biological life is not compatible with "make number go up" taken to its logical conclusion.
There is no need for the ASI to be conscious or to have any equivalent of human emotions to make the number go up.