This proposal is meant to establish a starting point for developing community consensus regarding downvoting.
Anyone can present a proposal to establish specific community guidelines for how to use DVs for other purposes, such as to stop spammers. If that is important to you, I encourage you to start that discussion and work in that direction. Part of the problem, imho, is that 'spam' is subjective and without clear guidelines, DVs for any and all 'perceived spam' is ripe for abuse by large stakeholders.
Personally, I think the 'mute' option is far better than DVs for dealing with spammers.
There is nothing stopping @proofobrainio from unilaterally muting spammers. Whenever you observe it (especially phishing spam), report it in the #spam-abuse channel on Discord.