There are definitely proportionally more Satmar than most other chasidim going of the path.
There are several reasons for that.
Satmar was more grouped as part of a city than part of a chassidus, so the whole area would follow. Notice that there is not a very strict uniform by the satmar, and there are different variations to what people wear.
That being said, they followed more a shitte than the actual rebbe.
After reb Yoel, there was no real leader, and with zalmoinim and aroinim things only became worse = diluted the leadership even more.
No leadership could mean way easier to go astray, if your living with a lifestyle where a Rebbe is needed.
Having those very strict rules (only very chnokkishe chassidim and viznits, are for instance into shaving heads of the ladies), amongst other rules, as well as being intolerant for people that want to go a bit easier on the rules (I'm not blaming, just stating facts), has the following effects on those that cannot or don't want to keep up:
Parents would have to fake that they go according to certain rules to keep their kids in school. Kids who see the parents faking are at high risk going off.
Also, someone that wants to be a little more free, but still according to mainstream traditional religious Judaism considered frum, will become an outcast, and pretty much considered completely off the derech.
Since he is gepasselt, he has no incentives nor brakes to stop him on his down hill ride......
Satmar it's famous for the lots of gemillas chasodim being done, but also famous for less popular things, as well as the highly unpopular anti-Zionist movement which is the closest to neturei karta.
Yes, there are entire neighborhood consisting of off chassidim (in the USA someone off can still wear all the begodim), and many are Yoilies....
To say that proportionally (meaning, taking into account their numbers) they go as little it as much off the derech as others is being very unrealistic.
