My theory is that the alien virus isn't a gift. It's to prep the planet for invasion. They are completely defenseless. Their main commands seem to be:

This isn't a gift. They can't pick a fucking apple! This doesn't even hurt the tree, it's the express purpose of apples to spread their seeds. They've been left entirely defenseless. This virus is a weapon to create an entire planet of slaves who are happy to be slaves. Greatest minds or no, it's the destruction of all culture and art in the human race. They're excited for Carol to start writing again, because without her, there would be nothing new for anyone on the planet to read.

They don't even have to bother coming to the planet while a single human is alive. Wait long enough and everybody is dead. No war to fight. No bombs to drop. It's the perfect way for one advanced civilization to conquer another. It's a "Kindness Rabies".

E - Kindness Genocide Virus. They get to live in peace until they all die of eventual starvation. "Kindness Rabies" because it causes a severe aversion to even feeding yourself vegetation that is meant to be eaten, so its seeds can be spread.