That the parent is currently at +5, and the grandparent at +1, speaks volumes about the people reading this story.

Are you defined by what you think of yourself or how others perceive you? Do you really think because you died with a gross income in your life of 10 million dollars, you will be remembered more than someone that only made $500,000 through their entire life?

the GP didn't suggest that you should devote your time to making money. They suggested that you should try to achieve something meaningful. And most people's self-perception is profoundly affected by their achievements, whether they like it or not.

I could be spending my time helping less fortunate people, or maybe working on an Open Source program that would benefit thousands of people. I may receive praise for such things, but what does this really do?

Your question is ridiculous, since you've just stated what those things achieve, and most people would agree that they're worthwhile objectives. What exactly do you consider worthwhile? A cure for cancer? People who hope to achieve that do not spend all of their time playing WOW.

Or, in 20 years, you can look back at the time when you played only video games. You can remember you had fun doing it, but did not accomplish anything with your life. You will have the memories of those games still, and the fun that you can while playing them.

Sure, you'll remember that you had fun, but you may also regret that you didn't spend your time more productively. Most people have goals that they'd like to achieve throughout their life, like buy a house, or achieve a certain level of education, play some kind of sport, or raise a family. Something that's nice about these goals is that, once achieved, they represent a tangible reminder of your effort, and that the skills required to accomplish them can help you in other areas in your life. In most cases, they'll also raise your quality of life, and allow you to do things that you otherwise couldn't. Playing WOW doesn't seem to advance you toward any of those things. Once you walk away from your computer, you are no better off than when you started. 20 years down the track, you may want a house, wife, job, or degree, and wonder why you played games instead of trying to achieve them.

You're ignoring the idea that maybe, if you use your time wisely, you can play games and achieve other things. No-one is suggesting that you can't take time out to have some fun sometimes. If you start trying to achieve something, you might also discover that things other than video games are fun too! (Shocking, i know.)

Some people feel that they have to help others, and do things beneficial to society, so they can be defined by society as being a productive member. And the only way they can satisfy themselves is to think that what they've done with their lives has made a difference (no matter if it really did or not).

Things that are other people admire are typically things that they'd like to achieve themselves. The point of being productive is not to gain other people's good opinion, but to satisfy your goals in life.

Just because you think something is wrong, doesn't mean it is. Even if laws say that something is wrong, doesn't mean it is. I feel that psychology hasn't fully caught up with the concepts of MMOs, so they tend to be compared to drugs or other bad addictions.

This is getting off-topic, but what exactly is wrong, then? Also, I think psychology is precisely right in comparing MMOs to drugs, in that using them is a lot of fun, but ultimately pointless. The tragedy of bad addictions is that you waste your life on pointless activities, when you could have been doing something worthwhile.