As with any art piece, some people will see it and think it's amazing, others will find it ugly and unappealing, and there will always be people who just want to walk past without bothering to pay too much attention.
The "game" is not about completing challenges like you'd expect. It's about having an experience. Personally, if I could recommend one, and only one, piece of art in any medium as something that everyone has to look at/experience, it would be Journey. That's not necessarily because everyone will like it, or even because everyone SHOULD like it. The reason I think it's something everyone should play is because EVERYONE HAS AN OPINION ABOUT IT. I find those opinions extremely interesting. If you show heaps of people a painting, then ask them about it, you'll always find at least a few whose "opinion" will just be a description of the facts about it. With Journey, I'm yet to see anyone who didn't come away from the experience FEELING something. Even if that feeling was just a sense of disappointment, or the desire for something more involved.
To me, that's more valuable than dragging someone with no interest in paintings through an art museum and having them say "it's a woman. With a ferret or something." while looking at one of Da Vinci's more well-known works.
There are people who study art and think Da Vinci is overrated as an artist. There are art critics who can look at something by Picasso and tell you it's ugly and terribly done. There are sculptors who are unimpressed by the classic ancient styles and say they're just repetitions of a process, however skilled, and not truly "art". Many people who aren't critics look at these works and develop precisely NOTHING in the way of emotional attachment to them.
The same thing applies to every game I've played except Journey. The fans and critics get into the game, enjoy it, experience it, work to understand it. These people develop an opinion, whether consciously or through the natural process of enjoying the experience. They develop an emotional response to the game based on what happens. But some people will take a look and have a try and... feel nothing. Even some critics will be left with no sense of a game beyond "meh..." after playing.
But in my experience, with Journey, that doesn't happen. This thread, with someone saying they "don't get the hype", and calling the game "dull" and "boring" among other things, is the closest I've seen to a neutral emotional response, and even that reaction has been shown to be emotionally driven to a greater extent than similar reactions to other games.