The author has some very good points, but they're cluttered up with a lot of petty junk, so I think he fails to make his points well. And the mega-annoying Internet Explorer sound doesn't help at all.
There are two points that he makes that I consider to be really valid criticisms:
1. The D&D mechanics (particularly ballooning hit points, armor class, and saving throws) don't reflect reality very well, and therefore don't enhance players' imaginations very well.
2. D&D doesn't reflect its genre very well. I have ranted about this myself with criticisms like the mundane feel of monsters and magic in D&D, and the odd nature of advancement. A D&D game really doesn't feel much at all like fantasy fiction; it feels like D&D.
But do y'all remember the "Worse is Better" essay? That essay ended up arguing that the "worse" systems that superseded the "better" systems did so because they had other features that ended up being more valuable than the features of the "better" systems. And it's like that in D&D too.
Here are the features that make I think make D&D stronger than most other RPGs: (I mean 'stronger' in a commercial sense, but also from a point of view of appealing to me.)
1. D&D's popularity is itself an advantage. It's easier to find people who play D&D, and there is much more material produced for D&D. But this feature is less important to me personally than to the other two.
2. D&D provides a lot more support to new players than most other games. It's true that D&D makes it harder to play anything other than standard D&D, in a way that GURPS, for example, does not. But D&D makes it much easier to play a standard D&D game. Some particular things that help with that:
- monster levels make it much easier to guess at appropriate opposition for a party.
- random treasure tables actually do help.
- (I had more points to add here, but I've forgotten them--I may add them later.)
3. Most importantly, though, D&D provides a paradigm. I know what to do in a D&D adventure--you beat up the monsters and take their candy. By contrast, I've been fascinated by Victorian RPGs like Castle Falkenstein, but I don't know how to set up a Castle Falkenstein adventure--and this has kept me from running such games.
These were the reasons that I chose to use D&D for my first campaign, with the expectation that my next campaign might be something different, once I have a bit of experience. I think these reasons are pretty good reasons for a lot of people to start with D&D. These are the reasons D&D wins out.