8-Chan summed up in 3 posts.
But seriously, I can understand the issues people have with it, but for most I'm willing to give it a few chances.
Right now though the kids are the biggest issue for me. For instance the end of the episode has a "moral" that you should trust your kids more, however, from what I saw in the cartoon, there is no reason for Donald to trust his nephews since they have shown that they are scheming too much. 1) Planning to Hotrod the houseboat and sail around a bit. 2) broke out of the room they were told to stay in (though with what they were given I can forgive that), and 3) changing the map for a more direct route but much more dangerous.
However, this is before Scrooge became a part of their life, and as Donald said, "I can't keep them out of trouble, maybe you can teach them how to deal with it". If scrooge starts rubbing off on the kids, it will be good, if they stay these troublemakers that tag along because it will be "fun" rather than "We want to help" then there is an issue with the writing.
Webby right now looks a bit too spastic for my liking, but again, I can see it for how she is. She is a little girl that was not allowed to leave a mansion/her caretakers employers home at all, she didn't even have a fast food burger for kripes sake, it's apparant that actually having people around and actually getting to do things would have her excitement go off the charts, again, if this mellows out to bursts of excitement at decent times not 100% all the way, I can see this being a decent cartoon.
Right now this starting episode feels like worldbuilding, a bit rushed I think though, Atlantis should have been a later episode or it's own 2-parter (seriously, if the city sank and everyone died who the hell carved the mural explaining, right side up might I add).
All in all I think there is potential, hopefully we keep seeing real places/real mythological treasures in this series, and hopefully they can be fleshed out more as well.