I hope you realize that Japanese insults are capable of converting to several things in English, it's just that subbers prefer to use the terms that convey the same meaning, but they seem more extreme. For example, 'chikushou' can mean 'darn' or 'damn', but subbers prefer the latter, and 'fuzakeru na' is literally 'don't lie' or 'don't joke around', but I saw some subs translate it as 'stop f***ing with me". In this case, 'a**hole' and 'jerk' are both correct.
With this in mind, anyone who watches subs just for 'the cursing' are very sad people. Aside from having this emphasis that "cursing automatically makes a show more mature", it seems that they'll just mindlessly read anything displayed at the bottom of the screen without even trying to listen to the actual Japanese dialogue. I bet if a character, who's ready to eat a meal, says 'itadakimasu' and the subtitles say "Let's go kill that guy!", those type of people would actually believe that's what's being said. I personally prefer subs over dubs, but I do pay attention to the actual Japanese dialogue. For that matter, I'm actually taking an effort to learn the language so I won't even have to be dependant on subtitles all my life.