I think the author doesn't like that with read receipts the people she's ignoring can definitively point out the fact that she's ignoring them. Before read receipts she could pretend that she didn't see it or missed it or a whole host of non-truths where it's socially unacceptable for the sender to imply anything otherwise.

Now the sender knows that the author is ignoring them and (perhaps worse) the author knows that the sender knows this. I think this is why she hates read receipts and what spawned this article.

On the opposite side, I like read receipts - but I also don't routinely ignore people who are messaging me.