This is one of those things that puzzles me because the reports vary so widely. I've always thought my 4Runner was very quiet for the type of vehicle it is. Considering the tires, high profile and squarish shape, plus lots of non-smooth features such as running boards, roof rack, big mirrors, etc., I'd say it's very quiet in relative terms and surprisingly quiet in absolute terms.
Maybe it says something about the other vehicles you drive or have driven recently. If you've been motoring around in a Lexus sedan, the 4Runner will sound pretty loud.