That causality is wrong. The vulnerability doesn't exist because Samsung products are attractive to exploit. It's a brain-damaged driver (exposes physical memory directly, which even /dev/mem doesn't anymore; and it's created with global write priviledges, meaning that literally no one with a clue about security ever looked at it). Samsung screwed up badly here.

A microkernel wouldn't have helped them here -- it looks to me like this driver exists precisely to defeat the existing protections that prevent userspace access to device memory. If that was the requirement, no kernel architecture would have helped this.

This problem (carelessness) cannot be minimized by micro-kernels or any other technical system, as this is not a technical fault. Samsung parked the company Mercedes in the middle of nowhere and left the key in the ignition and the engine running.

You may have done the same thing before - created a network share of your photos for others to see, but forgot to set the permissions to read-only instead of writable? This is exactly what Samsung did - they specifically marked a device with direct access to the devices memory as writable by everyone.

There are simply no technical solutions to incompetence ;) - this should never have made it out of engineering, let alone past QA.