I'm just back from a reading binge of 26+ novels/memoirs/proposals.
I didn't read all of them start to finish. My practice is to read until I have to say no.
Often that's within about 100 pages.
But for a couple novels I knew I was going to say no, but I still read the whole thing cause I wanted to find out what happened. That's VERY good since it means I was interested even though there were problems with the book.
Both these novels had undergone revisions while they were pending in my reading pile. (Probably more than a few, since you can't keep an author from tinkering unless you tape their hands to something, and even then they try to type with their noses or toeses).
What happened with both the books was the revisions changed key pieces of information about characters and the time line. That change had NOT been integrated into the manuscript as a whole. So, someone who majored in math in chapter 206, was introduced as someone who majored in physics on page 2.
When you're revising, and familiar with the manuscript, you don't see that.
When I'm reading, and page 2 was six hours ago, I do.
This is not the kind of meticulous writing I look for.
Enough of it, and I'm much more likely to stop reading.
So, how to fix it?
Well, don't stop revising. I often find that my 101st revision is where the really good stuff finally gets on the page.
When you finish a revision you need to let the manuscript lie fallow for a week, then go back and read it all the way through again.
And you probably need to read it aloud to catch the homonyms and wrong words. My favorites are hoard/horde, and stubble/stumble. (In fact, I caught your/you're in the title of this blog post ONLY after I let it sit overnight.)
In other words, if you revise, you need to make sure you've improved the ms, not created problems for yourself.