It's pretty safe to say that the core audience of this game probably has never even heard of EGM or VGCharts.com for that matter. It's not aimed at us. It's aimed at the same people that bought Nintendogs. I saw this game, and instantly thought of my 7 year old daughter. My son already has a Wii, but part of the reason I bought her, her own Wii was so that she could play Endless Ocean. It is a fun diversion. People enjoy themselves doing alot of things that have nothing to do with conflict. Playing a guitar, walking a toepath through the woods, watching TV. My daughter wants to be a marine biologist when she grows up and loves going to Seaworld. When we went to Typhoon Lagoon in Disney World we got to do the dive in the shark tank. The sharks were of the harmless variety and there was no danger, no conflict, or air gauges, but we had a blast. My daughter will love exploring an ocean that is endless. It's aimed at those people. Some people in the video game community are just bent because this game has totaly ignored the self proclaimed "hardcore". Just deal with it. It's not the end of the world.
I agree with almost all of this, although Endless Ocean isn't exactly a game for children -- any more than biology and Scuba Diving would be. Children would certainly enjoy the latter (and be informed by the former), but those are definitely adult activities, as well.
If we are to go by generalizations (which I happen to think are largely correct), it's important to remember that the Wii has an adult audience as well, one that is on the whole older than the 360 or PS3. The defining games of the PS360 are for 18-30 year old males. Games like Endless Ocean or Wii Sports can be played by children, but are also enjoyed by 50 year olds. In a way, this game is more adult than, say, Gears of War -- a game that is only "mature" in the sense that there is so much senseless violence that kids probably shouldn't play it. You'd have to search far to find a grown woman over 40 playing Gears of War (I'm sure there are some), but you'd find that Endless Ocean appeals much more readily to adults.