You need to communicate. Clear, concise, eloquent, and precise use of english* allows this to occur. The reason that this breaks down is because too often people resort/revert to using slang or not thinking before they write.
You end up with text equivalent of 'verbal diarrhea'.
I do not know what 99% of those "pacman" faces are supposed to mean. Maybe it's because I'm on the Autistic scale and I have trouble reading expressions, maybe it's because I'm an 'old fart' and these kids need to get off my lawn.
I understand that emoji are just a simple evolution from emoticons. I do not understand why we needed to expand on:
=) or =(
TFA posits that emoji are "body language" for internet communication. If people just wrote what they fucking meant this wouldn't be an issue. (Look at the constant misunderstandings that arise from sarcasm or lack thereof, for an excellent representation of poor writing.)
*Disclaimer about my own ignorance: I don't know if non-english speakers suffer the same follies as english. English is a sloppy, imprecise language. It takes effort to clearly convey a message that cannot be misconstrued.