Just 2 weeks ago, I felt a large "bubble" in my dog's ear while brushing him. The next day we were at the vet and she handed me an estimate for a surgery my dog needed on his ear that was almost $1100. I had nowhere near that amount in my bank account, so I put it on my credit card and let them do the surgery that my dog needed and have already gotten a check from the pet insurance company for the entire amount, less my $200 deductible.
So yes, pet insurance is worth it to me. My dog got the surgery he needed, and I still got to eat and pay my bills this month. If you can afford to shell out an unexpected $1000 (or more) for your dog, then maybe it's not worth it for you.