The fundamental problem is that Facebook's "agreement" seeks to undermine a core aspect of the web, which is that everything --- everything --- sent across the wire is to be interpreted as a suggestion (not a requirement).
The recipient is free to enlarge the font if they have poor vision, they're free to pass the content it through a text-to-speech engine if they're blind, they're free to strip out all the Q's and J's, they're free to turn down the volume on videos, etc.
Facebook can try to impose their will, but all they'll end up doing is looking like a bunch of empathy-deficient, user-deaf nincompoops.
The recipient is free to enlarge the font if they have poor vision, they're free to pass the content it through a text-to-speech engine if they're blind, they're free to strip out all the Q's and J's, they're free to turn down the volume on videos, etc.
Facebook can try to impose their will, but all they'll end up doing is looking like a bunch of empathy-deficient, user-deaf nincompoops.