@Pcm97 2 years later you get your explanation, with decent management of uncommented and unliked works, it's still possible for someone to generate a random sentence (or even copy and paste, if they don't get reported) on just enough works to beat the current first at the last minute (or rather hourly check and end-of-week check). Objective and relevant to the work doesn't mean "quality", it could be something completely random and still be awarded the full score as long as it is within WHentai's terms of service.
As TOFUK said back then, a lottery system using EV purchases would still be better since EV purchases allow the site to exist and maintain infrastructure (with adblockers, ads probably don't generate that much money). Spam if taken to full extent will do the exact opposite, it is even possible to comment on works without even browsing them, or works that don't exist in the database. With VIPs being deactivated after 3 months (requiring someone who did not purchase EVs to start "contributing" and "encouraging" artists again), that means a ~12-week-cycle for all accounts engaging in this.
The "spam reward" discrepancy in the top three likely plays a role in this. Not that it matters much though, since if commissions start to cost 1000 EVs or more after the pricing and payout adjustments, it fully takes care of the problem by ******* even spambots, script users and very quick people (with deep learning advances, there will soon be a way to automatically produce objective comments as well in less than a second) to actually purchase EVs. Multiple accounts also are not always obvious for similar rea***s, and there are other cases that the system wouldn't be able to monitor - at this point, it becomes too complicated to tell what's going on and borders on speculation or even conspiracy theories.