I think it would get a lot less hate if Google just made it possible to opt-out of them without having to download some third-party browser extension (which is actually what Google's AI summary itself suggests I do when I ask it how to turn itself off!). A small "opt out" link on the top of the AI suggestion would make most of this hate go away, and would make me stop paying for Kagi, if Google cared.
I also find it extra frustrating when AI summaries appear when I search for correctness-critical information, e.g., "what temperature to cook chicken?" or "can I eat old eggs?" --- why force me to scroll past an entire page of AI generated, 1%-chance-of-being-a-literally-lethal-hallucination "summaries" in order to find the CDC's actual recommendation? I don't want to play Russian roulette with my health hoping I don't get a hallucination, instead I just want the authoritative answer. Which Google did an amazing job at until a year ago, and Kagi is doing a pretty great job at now.