In all mediums there are different scales, some pieces of media exist to be consumer material, some exist to be thought provoking analysis. Video games are no exception to this rule, while a lot of video games are obviously made with consumer in mind, there are also a number of video games that exist to be artistic. Journey is the example that gets thrown around in these arguments and for good reason, it takes advantage of the player aspect of video games in order to put forward ideas on cooperation between people. To put my point in a less snobby way, essentially all media is made for different reasons, some for arts sake, some for profits sake, video games are not an exception (Even if to a lesser scale).
Comparing the average video game to the average movie will garner you similar results. I mean, if we're comparing The Lego Movie and GTA V, neither are exactly art. But that's the point, they aren't meant to be. If people are comparing Watch Dogs to Citizen Kane, then yeah, they're being stupid, but it's only the same as if someone compared Journey to Alvin and the Chipmunks. All video games are not art, just as all movies are not art. It really depends on the aim of the thing in question, what's it being made for. Video games have the added bonus of player interaction, which allows for very unique ideas to be portrayed.
So to answer your question, video games are the same as any other medium, they can be thought provoking or disposable, it all depends on the aim it's going for. Not all video games should be taken seriously, but that's the same with anything else too. Sure artsy video games aren't seen as much, but I'd argue that video games as a medium is only really getting comfortable recently, so there are bound to be less examples. The potential is there though, and we have games that prove that. I think when Video Games maybe start to become more accepted, then they'll start having more of an impact, but it's not off to a bad start. Journey wasn't exactly ignored, was it?
As for why people are so attached to video games, that's a whole different idea, and I will spare you the essay on gamer identity and why it means a lot to people.