I disagree. I'm a mod on a reasonably large subreddit and I regularly get approached about promoting certain brands or blogs. I've never accepted any of the offers as I don't agree with gaming the system but undoubtedly plenty of people have.

Marketeers are getting wise to Reddit. They know if they hit a sweetspot the reddit can make or break their brand over night. Soliciting "reddit celebrities" is naturally going to be a tactic many people employ.

Useless != meaningless.

Reddit karma is (mostly) useless, but I think the poster's point is that they are meaningful to a great number of people, otherwise they wouldn't be accumulated and fought over with such zeal.

People's egos are tremendously important to them, and the people around them.

I'm a long time Reddit and mod for a big subreddit - it's not meaningless. There are TONS of perks you get when having a high comment karma count. Physical, actual benefits.

This is where I don't get the duality of how people perceive the internet as a medium.

We want the products we build that aren't (to counter your definition) "in the real world" to give us salary, a future, wealth, whatever... but you flip the viewpoint and someone doing something they wish to do "not in the real world" is completely meaningless (and this implicitly has no value). The fact that people achieve A surely means there are endless scenarios where B is not true.