The relationship doesn't really work as report=moderator action.
There is a stronger relationship between the reporting and moderating process now than there used to be, but that is a consequence of the changes made to moderation. NS and Raen did not rely on reporting for their moderating. While they did respond to reports, they also looked into the forum on their own time as volunteers. They read the forum as members (NS was a BioWare employee originally, if I'm not mistaken) and thus their moderation took many forms, of which responding to reports was only one form (albeit was likely the most common one.)
With the shift to employed moderators, the nature of the relationship has changed, and it seems likely that reports do now make up a larger percentage of what brings moderator action about than they used to.
But that shift is not as pronounced as people think. A single report could draw a moderator's attention to a thread, who then feels there are reasons to look over the thread. At that point, it seems pretty likely that they aren't going to focus as much on the substance of the thread as they are the more obvious violations they see as they pass over. It's doubtful that they are taking the time to look much at names or read deeply, since this is their job, and they may well have a lot of reports to get through. It is likely that images - whatever they are - are eye-grabbing, and thus pretty likely to get noticed while looking over a thread.
None of which is meant to be interpreted as my thoughts about how it should work, only that I'm pretty sure that's how it does work. People are too focused on the idea that the people reporting are the issue. I don't think they are. Even if they were, it would be impractical to address the issue from that perspective for forum members.
I still think the recent uptick in moderator actions is the slowly ebbing lack of discretion that comes with experience. It's what happened when the first slew of employed moderators were brought in in 2013. Everything was against the rules, bans were being handed out for everything (rule violation or not) people were being banned in error with no recourse, and none of them were even filing reports about any of it, so there was no way for the devs/mods with experience to even sort out the mess.
There was another recent influx of moderators, and a significant increase in the number of moderator accounts being used. I think the uptick is a direct result of that (and that, mostly, BSN is just as BSN as it has always been.)
It's not as bad now as it was a few months ago, when the new ones first came in, and as time goes by, they'll use discretion more and more, and the more frivolous reports or harmless images will go ignored more often.
I also think we just got used to the place being incredibly lenient for about a year. I admit, that was nice, but it was the exception to the way it usually is. Hopefully we'll settle back to something like that again.