Well I agree. I think it would be nice if it came with some small perks as well as reporting is pretty much a thankless task and even with a badge that doesn't really come with any benefits, especially since it's a time-consuming task and you're helping out the forum a lot. The only previous perk to reporting was that if you were a very high reporter it made the chances of becoming a mod much higher but I can't remember the past time someone was made a mod from sheer volume of reports. I guess when the time comes when theymos feels we need more mods the list of reporters will be consulted but personally I feel like there's a couple of users who have already paid their dues and would be beneficial as staff even if it's just as patrollers (and they could certainly help out with post approval if that ever happened).
I guess that was me back in August 2018 (?) I can't remember exactly when I was made a moderator, but I was made a moderator around 38/39k reports, but there's obviously a few users here who have been reporting significant amounts for months, and there's no sign of them becoming a moderator yet, and I would consider some of them pretty trustworthy too, but then again I don't see too many reports within the sections that are in my opinion in need of moderators.
Reporter badges are definitely going to encourage certain types of users to report, generally those that like to stick out within a community, and I think that's fine. You'll find a lot of organizations offering achievements, and badges to encourage students to learn. For example, a number of language courses do it, as well as when we were all back in school as a kid we had a system where they would put stars on your report card if you done well etc. It does work even in adulthood.