While I don't have a problem, if someone else likes it, I'm not really a fan of Wataten. And yes, it's the edgy jokes.
It's not that there is one edgy joke about sex offenders, it is that it seems the entire anime appears to be such jokes. It's joke after joke after joke.
That makes it quite uninteresting to me.
Like, there are anime where a character seduces the teacher for laughs, and that's probably alright.
But then, this anime is just "fall in love with little girl" "bribe her with candy" "snap photos" "I'm calling the police" for laughs.
It's not that I find it uniquely offensive or distasteful, or that I think it is obscene to the eye, it's that it's just not interesting to me.
To me, it's an anime trying far too hard to be edgy. I'm not particularly surprised this anime doesn't seem to have gotten a second season.
I can see why it *might* be uniquely offensive to someone.
The humor references sexual offenders specifically (and rather gratuitously), i.e. candy, rather than simply engaging in edgy scenarios.
But, then, the potential for offense isn't something that is particularly relevant to me here.
Also, this is a tip of the iceberg, because the anime really is joke after joke after joke.