I'm referencing this question, which highlighted my comment about disliking anonymous downvoting. The result of that discussion was my education that anonymous downvoting is in some ways integral to how the site works and is a system that is working as intended. However I made it clear I dislike the concept, and I'm curious if I'm allowed to continue to speak against it when it happens?
I'm curious if I'm allowed to continue to speak against it when it happens?
It depends. If you're furthering a productive Meta discussion, then by all means.
If you're complaining about it in comments on posts, then no. You'd be disrupting the site with off-topic chatter. Such comments are routinely deleted and you would likely face further moderation if you continued to do it. This is no different from commenting on any other issue other than the content of the post.
Addressing the anonymous downvoting specifically, there's not really much that can be done. Meta.SO gets questions on a regular basis asking for the feature of knowing who downvoted your post, or require a comment when downvoting. It never works, because anonymous downvoting is by design. Throwing barriers into the way of downvotes would mean downvotes happen much less often, and site quality would suffer as a result.
In the general sense, enforcing a policy (or attempting to enforce) a policy that is unpopular and the community doesn't agree with, tends to be looked on extremely unfavorably. There was something similar that happened on Physics, and it's seen as working against the community consensus. Most of it is because it's disruptive, and using random questions as your soapbox.
There will be times you don't agree with the community consensus. I'm not a fan of lore questions at all, but the community has decided we want them. It becomes a personal choice whether or not this is important enough to you to continue participating in the site or not. But starting a one man crusade to get people to follow your policy is not the correct action, and trying to do so will eventually make the choice for you.