Boris Ekner wrote:
Not applying to be the grammar police...
"Do people read what they wrote..."
Correct is:
Do people read what they write?
or
Did people read what they wrote?
Sorry, but I think all three forms can have a relevant meaning in this discussion.
"Do people read what they wrote..." could mean, do people read what they just wrote, that is, do people read what they wrote immediately after they've done the writing. This is part of the active process of the writing itself, after completing a sentence or paragraph. It concerns checking what has already been written before they consider it to be finished and moving on. It could take place in the middle of the post, or at the end. A present tense action concerning a past tense action. (It could also mean, do they read what they wrote at some later time - after posting, next day, or whatever, too late for correction.)
"Do people read what they write?" means, do people read what they write, as they are doing they writing, and not before they consider it ready for posting. This is a correct-as-you-go approach, as opposed to the above phrase, which refers to re-reading a sentence or a paragraph that they had thought had been written as they wished, and are going back over it, checking for accuracy. This is all present tense.
"Did people read what they wrote?" means did the people read what they had written after they think they have finished, or at some later time. This is similar to the first phrase, but is all past tense - they think the writing is finished and that they are no longer actively involved in the writing, unless they discover that they have to go back for correction.
All three phrases can be relevant. I myself use all three, from time to time. I correct-as-I-go, I pause to check what I have written, and I re-read the entire post before hitting the send button.