I have a great hunch as to why:
- You don't need writing for survival, you need food, water, and shelter for survival
- Reading/Writing consumes many resources (The Buddha was against destroying plant life)
- Evidence shows that reading causes headaches, nausea, and myopia indicating that our brain was never specified for reading and writing
- The achievement of arahantship does not rely on reading/writing but instead on the ending of mental fermentations
- Illiterate people can learn and accomplish the same things as literate people learning orally or with images or video
- Oral recitations may benefit self-discipline, memory, and concentration
- Learning things orally consumes very few resources and doesn't require that someone know how to read/write
- The Buddha predicted that the pure dhamma would disappear within 500 years...no amount of writing things down would've changed that
For me personally I notice that I can remember most things much better if I orally recite it a few times rather than if I try to visually memorize it so oral recitations are really useful for me. I had memorized many things this way like my credit card numbers, driver's license number, etc...
I also think that humans in general may learn many things better without writing (learning orally, using images, video, or through experience). So it may be a good direction for society to abandon writing or lessen the use of writing in the future.
Just imagine if you achieved arahantship would writing things down really help anyone out in achieving arahantship (the ending of mental fermentations)? It's experience vs. reading. Would reading archery books (with no images, video, etc...) cause someone to become an excellent archer or would the actual experience of practicing archery cause someone to become an excellent archer?
In many conditions reading something won't matter or help much at all whereas experience really matters (for everything in general).
I notice that even if I give exact precise instructions a lot of people still won't get it or achieve anything.
So it makes sense to me that The Buddha didn't care about writing things down.
In the future since a food/water crisis seems likely writing may be abandoned or only reserved for some few. We're cutting down trees and using lots of resources on literacy and reading/writing instead of on food, water, and shelter.
The difference between literate vs. illiterate is oral vs. written. That's really it.
Remember in the Dhammapada The Buddha says:
"Much though he recites the sacred texts, but acts not
accordingly, that heedless man is like a cowherd who only counts the
cows of others — he does not partake of the blessings of the holy
Little though he recites the sacred texts, but puts the Teaching into practice, forsaking lust, hatred, and delusion, with true wisdom
and emancipated mind, clinging to nothing of this or any other world —
he indeed partakes of the blessings of a holy life." (Dhammapada, 1.19-20)
It seems like The Buddha wanted to encourage people to act on the teachings that lead towards arahantship rather than encourage people to focus on superficial things.