You have no idea how cheating in games works. They dont touch the exe, they touch the memory. You can not stop game hacks with any first strike system, Its 100% reaction based, like anti virus software.
Well, that would certainly make it harder for Blizzard to stop cheating. But not impossible; they would just need to require clients to have locked down memory. That is probably impractical (for example, it might well mean they would have to sell their own locked down client devices), but it's not impossible.
> You can not stop game hacks with any first strike system
Sure you can. But the system might not be practical.