First, I didn't say that Google "wanted to reward abusers". I was simply countering the parent commenter's use of Rubin's payout as an example of what typically happens when an executive is fired for sexual misconduct. It is absolutely not representative, and Google changed its policy as a result of this: "Alphabet said Friday that it will prohibit severance packages for anyone fired for misconduct or is the subject of a sexual misconduct investigation."
But since you brought it up, the fact that Google changed their policies in response to the Rubin (and Drummond) situations and did not caveat their policy with "except in the case where there's a performance bonus, which we'll still totally pay out" implies that it was a choice to begin with.
Also, even if there was a performance bonus that Google felt they might be forced to pay in litigation they could still have fought it to demonstrate a commitment to not rewarding executives preying on subordinates and to preemptively address potential employee backlash, which was entirely predictable. Google has effectively infinitely deep pockets and did not need to preemptively surrender.
And in addition, Drummond and Brin were both involved in the decision and both had affairs with subordinate employees. So, while I wouldn't say that Google had an active goal of "reward abusers", it's quite plausible that the specific, small group of men making this decision on Google's behalf may not have been particularly inclined to punish behavior arguably similar to their own.