It is true the overall tone of the show is a bit mellow, but this is clearly the point: it is meant to be heartwarming, and yes, it is addressed more towards children (e.g. In the wild dog episode, the successful hunts are not shown, just the afterwards meal). It is still enjoyable for adults though; it's not at the level of Our Planet, but still a very nice and informative series. I do wish we would have a bit less of 'magical' and 'miraculous' - rather, this is exactly the opposite - but that's not a real complaint.
In terms of content, obviously some animals (bears, elephants, sea lions) win the cuteness contest. In contrast, our cousins the chimps are, let's face it, a bit disgusting, with their butts and their grooming each other then eating what they found in there, but well, they're still not the most embarassing member at the hominid family gathering, isn't that right, Sapiens?