Some real damning words here Steve. Some of it is justified others maybe not.
In terms of the point you made about questions, I think that this can be pretty valid, but it depends on the person asking. I think one of the biggest problems is the attitude of those in their roles, be they new or old. Some questions you see are clearly from those with little to no experience with SQL, but some ask very good questions; others don't ask they request (or even demand) that the users here, or on other support sites, give them the solution.
Those that are new and showing effort need to be praised. No matter how low their understanding, if they show they've tried and why it's not working then you can see straight away they are someone who wants to learn. Maybe the documentation is too hard for them to understand (some isn't easy for newbies to get), or maybe they've misunderstood how something works; we all do it. I welcome these people to the industry and look forward to them bringing their insist in the future once they know the product.
On the other hand, we have those that don't want to learn and this article definitely points the figure at them. They know what they "know" but have no interest in changing that, for better or worse. When they have a question they aren't interested in how the solution works, or that actually the problem they have wouldn't exist if they changed their approach. If they get a solution, and then they need more then they ask those that "helped" then before for help (support, aka free consultation). These are people who's attitude need to change. They certainly don't know the product, and will fall far behind as it moves on.
I know my areas of knowledge is limited. Indexing is a huge gap in my knowledge pool because I don't get to use them in the production environment the way I would (due to our application). I know enough to get by, and can see the obvious but I look forward to using them more intimately when I move on. Replication would be an interesting thing to learn too, but I suspect I'll end up going down a SQL developer route, rather than DBA and will likely therefore not get the chance to try it out in anything other than a sandbox environment.
Excuse my typos and sometimes awful grammar. My fingers work faster than my brain does.