It would be difficult, no question there. They aren't calling it a "frontier" because it's a simple problem, because it's not.
And actually, with (normal) e2, you can write 0's, you just can't write 1's. So maybe, just maybe, it would be possible to encode a virus in the pre-existing data. Who knows? But IF it was possible, it would be difficult but very rewarding.
The BIOS has been around forever, I suspect that if it was actually possible to do something evil with it, it would have been done by now. Consider bootsector viruses for example.
Also, how rewarding would something like this actually be? I'd imagine detecting OS, finding network drivers/apis to take advantage of them would be extremely difficult and not worth the effort.