Double KO Capcom's Street Fighter V Installs Hidden Rootkit on PCs

How could be a programmer, who has enough patience to read documents and has knowledge to implement the Windows kernel driver which does,

1. offer IOCTL serivce 2. disable SMEP 3. execute user-space code from kernel.

, NOT notice the very program he is writing has serious security vulnerability?

How could he not notice and saying "Wait, Am I writing rootkit?"

The official Twitter said to expect a "PC rollback solution soon".[1]

Sounds like this capcom.sys should be added to AV signature lists...

I agree. Malware has been known to install vulnerable signed drivers to get unsigned kernelmode code execution.