I didn't really like the story. It was pretty well-written, and interesting, and the way the Stalk thinks and the reason it's there is interesting too, but I didn't actually like the story, per se. Can't really explain it.
Kudos to the author for vomit-tech.
Michael Crichton, in "Sphere" via the character of Norman, asked what would happen if aliens came to our planet and breathed air but excreted toxic gas... or something similarly alien, so alien that it was impossible to understand or killed us inadvertently. I rather think the Stalk wasn't trying to hurt us; it was just trying to learn more. About a race that, when children repeatedly ask "why", has been known to ask its offspring to "go play with your toys and stop asking so many questions".
Interestingly, Norman's focus group in "Sphere" also was overseen by a general who came in, read the report, looked at the alien they'd "created" for the purpose of their exercise, and said "where's the anus?" I read "Sphere" when I was 12 or so, and that made me laugh.