There's a gamingonlinux article which might explain a bit.

Very roughly, a few alterations to the anticheat to make it work on Wine made some of the anticheat's workings apparent, which in turn allowed people to work out new exploits.

Wine is an excellent tool for reverse engineering. Additionally, we had to disable many antitamper checks to make Hyperion run on Wine. This has allowed interested parties to learn a lot about the internal workings of Hyperion, relevant to both Win32 and UWP. As the initial shock of Hyperion’s release started wearing off, many people have begun discovering the various angles through which one can learn more about the inner workings of Hyperion.

As to why all the anticheat stuff matters so much, I'm not quite sure.

2 big reasons I've seen.

First is idiot csuite/suits at the top who think linux = haxxing and they somehow lose business by supporting them.

Second is kind of true, that people have trouble running on linux and go to official forums asking for help, or leave negative reviews that they couldn't get it to work, which isn't fair to the developer.