A hateful screenplay
****spoilers abound****
Leave aside the messiness of this screenplay--typified by the "comforting" ending with its 'oh, we'll see each other in heaven' emoting, which mixes poorly indeed with the idea that the instrument of this Divine Providence is an entity that thinks nothing of making zombies of people, manipulating events to make people poor and frightened (so they'll be more likely to fail their moral test), and maiming children.
Beyond all that, this screenplay contains some loathsome and revolting messages.
Number one for me: the message that it's better to COMMIT MURDER and to leave a child effectively parentless than for that child to be blind and deaf. As if being blind and deaf were almost literally 'a fate worse than death.'
How delightful for people who are actually blind and deaf to get kicked in the head by the popular culture yet again. How hateful of Kelly to provide them with this kick in the head. (Yes, even blind and deaf people manage to find out what's in movies. They are not inanimate objects. They are people who don't deserve this sort of thoughtless treatment.)
Number two: the "woman is the downfall of mankind" message. Yes, I know that Kelly's defenders (against the charge of misogyny for having all three 'button pushers' shown in the movie be women) cite the line spoken by the police chief. But what is SHOWN is what counts in a movie. I could almost guarantee that if all three button-pushers shown happened to be, say, black---if, say, the movie compared white couples confronted with The Box to black couples---then people would not be so openly defending Kelly.
The 'oh, it's mythic, an evocation of the legends of Adam & Eve and of Pandora, wow, so profound!!1!' excuses would be exposed for what they are, if not for the fact that we're pretty much "okay" with dumping on females in this culture. Again, if it had been a contrast between black and white people (as opposed to between male and female), the bigotry would have been considered inexcusable.
...a somewhat less significant Number Three is the fetishizing of physical deformity. I'd concede that this is merely unpleasant, as opposed to hateful.
But on the whole, this is a nasty screenplay (and movie). It's a shame, as Richard Matheson's original idea is so thought-provoking and interesting.