I don't hate query letters.
I don't hate them even a little.
Query letters work just fine and dandy for me. I meet a lot of my clients for the first time in the incoming queries.
I turn down more good, and publishable, stuff than I say yes to.
What that means is anyone who proposes to change to something/anything else has to show me how it will either save time, or create some other efficiency for ME. ME, not you. ME.
The only person who suffers when a query is "bad" is the writer. If anything bad queries make it easy to click "here's your hat, don't let the door bang your keister on the way out" button.
I realize the ways of literary agents are not supremely logical, and can seem arcane, and mysterious. I figure if I talk about how it works, otherwise befuddled writers might be able to craft a query for a book I'd really like to read. Win/win.
But I'm not looking to change the query letter system at all.
It works just fine for me.