Agreed. People are much more likely to be inundated by tweets and texts than by e-mails. Yes, they limit characters, so your prolix friends have to learn how to express their thoughts a bit more concisely, which might help, but they also encourage the communication of trivialities, and are more likely to demand an immediate reply.
"thought snippets" are more manageable than their lengthier alternatives. Recently, our team switched to a Trello board from a regular issue reporting tool and the time involved in thought transition/handling/visualizing per issue has reduced.
Lesser/Neater messages can pass on more information across the board, even if they are not comprehensive.
On the other end, excessively lengthy emails do not serve their purpose of getting their point across clearly as that can be removed in the information overload.