It was too confusing.
After a few back-and-forth comments about something-or-another, I ended up giving the following advice that, I hoped, got to the root of the problem instead of just polishing things on the surface. Some people who read this comment, including the author herself, mentioned to me privately that it helped them. So I thought I'd share it here too, in hopes that someone else might get good use out of it.
If you look at your query letter more in terms of presenting your premise rather than in terms of presenting your plot, it's actually a LOT easier to write and tends to not require so many words. You still need to focus on character, goal, stakes, etc. But I've found that I don't get lost in writing unnecessary details when I put more importance on relaying a clear premise/concept/hook.
The rest just naturally falls into place, and it starts with knowing your exact premise.
This isn't to say that you shouldn't have any plot at all in a query. It's a delicate balance. But approaching it from the standpoint of, What is my premise? rather than, What is my plot? tends to be easier to convey.
Premise is usually what gets me to start reading a novel, whereas plot is what keeps me reading a novel. All you need to do in a query is get someone to start reading your ms, so. Premise should have more importance there, in my opinion.
What do YOU think?