Does gaming addiction quality as it's own separate mental disorder? I don't know, I'm not a qualified professional in that area. But it is definitely a problem for some (or even many people) to be addicted to their games, or technology in general. And it's clear that those addictions hardly contribute to a productive life. I think the clear benefit of labeling game addiction as what it is, game addiction, and not something unconnected to it, is that people who do have that trouble are able to find validation that they have a legitimate problem. And hopefully eventually find real help if they are in need of a support network to get back on their feet.
The
counter article linked in the original article you posted, stating at least some of the industry's point of view, is however correct that this classification lacks much scientific research to validate it. I think we can all see clearly the effects of gaming/technology addiction, but does classifying it help if we know nothing past that it exists? However, the industry stating that, "The educational, therapeutic, and recreational value of games is well-established and recognized," is not a very good point, because it's a fallacy to assume that the fact that some games are beneficial, that means that no games are harmful. And it depends on the individual playing the game too.
So, the much more interesting question, and the OP mentioned this, is what moral issues do game developers face when designing games to be fun. Do we have a responsibility to avoid making our games addicting? Now, everything here assumes you believe that decisions should be made based on an ethical guideline of some sort. (IE, I'm not going to discuss the
legality of making an addicting game).
And as to that question, I personally believe that yes, as developers we should be concerned for our players more than how to best make money off of them (usually by using techniques like skinner-boxes to get people to keep playing, watch adds, or pay for extra content). This means a lot of things, not just concerning addiction. I think it's important that we avoid techniques/designs that are entirely designed to convince or even trick people into continually playing. The idea is, players should want to play the game entirely because they want to play the game, because they are having fun. Not to keep playing so they can reach one more level, one more story part, etcetera. That just makes the game more fun to play anyways. Some things in terms of design that should be considered are things like, where is the play again button? Is it easy to save and quit the game? For example, in Sea of Thieves, there is no way to save and come back to finish selling your treasure or continue a voyage later. Now, this is necessary due to it being the game it is, but as much as possible, I think designers should make it easier rather than harder to save and quit the game. Also, giving smaller rewards more often so players can stop playing on a high note (this is particular for games with matchmaking ladders).
Really, this just results in better games. And maybe I'm too idealistic, and you just can't make money off of a game unless you cram every micro-transaction you can, every skinner box, every number progressing higher. But I think EA proves that this can be taken too far. I tend to believe that making a more honest game, that remembers that your players are real human beings, gains some real benefits from the kinds of people who recognize that and buy your games because of it.
This is all nice and dandy, but it won't stop game addiction. As developers we only have very limited control over the choices or eventual addictions of our players. So for that reason, I think that the people funding the research cited as lacking by the game industry, is the game industry. The game industry may not be responsible for people's addiction, but they should
want to devote the time and effort into studying the field they are working in so that they can design and make games which are better products and are more healthy for their players. I think that is what will benefit games the most in the long run. And certainly, doing nothing, believing that all addictions are just inevitable, seems like ignoring an opportunity to really help a lot of people, even if it's impossible to help every single person.