It could be mistaken for actual text that would go into the final project. Lorem-ipsum is obvious fake text. I’ve had to explain to someone what it is before, but it was obvious enough they asked instead of thinking they should review the content of the text.
Also using Lorem Ipsum makes it easy to tell at a glance whether the site/app is using real text. Using generated real text would require a bit more thought to verify that the generated text should be replaced.