As someone who works in security, you should be extremely skeptical of their stated reasons, or even the validity of the data.

There were a LOT of divorces following that leak, citing the hack as proof of infidelity, but the reality is that the leakers could have added people to the data explicitly to facilitate uneven divorce settlements (e.g. adding a woman to the site in order to give the husband a means to demand no split of assets).

As much as it would be great to imagine hacktivist crusaders going after cheaters, there was a lot of money moved on the back of that leak, and in fact one of the problems with Ashley Madison was that prior to the hack it was used to essentially extort non-users, because anyone could create a profile with any email, but if someone created a profile of you, you had to both verify yourself with your ID (which they saved), and pay them money to delete it (which the leak revealed they didn't actually do anyways).