<p>Leaving aside the specific incidents you mention (though gave some of my reasoning on one of those in comments), I want to address the title question about whether new users should be able to ask duplicate questions.</p>

<p>The policy against duplicates is there for a <a href="https://stackoverflow.blog/2011/01/the-wikipedia-of-long-tail-programming-questions/">good reason</a>. Indeed, it's one of the major attractions of the site for me. That linked article, by one of the Stackoverflow founders, Joel Spolsky, points out something that he and Jeff Atwood (the other one) had noticed about forums like Usenet (which I also answered questions on back in the day):</p>

<ul>
<li><p>newbies would frequently ask the same beginner questions</p></li>
<li><p>old timers got tired of it</p></li>
</ul>

<p>I've been answering stats questions online in various fora since at least 1992 (before even the Mosaic browser existed), and CrossValidated is the first forum I've been a regular on that made it really easy to find previous versions of the same question, and which tried to solve the problem by making it easy to get new versions of questions pointing to old ones which already had good answers. $^\dagger$</p>

<p>As Joel pointed out, the problem with forums that don't do this is that you end up answering the same "standard" questions over and over -- and the more nearly beginner-level the questions are, the more of them you get (because there will always be more beginners than experts). So as a site grows, you spend more time answering questions you've already answered before. The answers tend to become perfunctory, since there's no benefit in putting effort into really good answers -- the effort will disappear into history under the flood of new questions and in a matter of days or weeks is forgotten. Effort is only briefly recognized, and we'd only be helping one person at a time -- one question, one answer, one person helped. After writing a few thousand answers on the internet, it starts to get annoying.</p>

<p>With CrossValidated, by contrast, it's worth writing a good answer, because your good answers remain easy to find even when they're old, and new questions on the same topic will tend to point to older (and hopefully more canonical) versions of the same question. If you want to contribute an answer to the site, it is best done at the same place as other answers, so that the best answers are all in the same place (instead of spread all over). That way, once you find any good answers, all the other good answers are there, and can be compared (and, hopefully, the best ones have the most votes).</p>

<p>Here, some of my answers are seen by thousands of people. [And while I was typing this answer yesterday, I got an upvote on an answer that was almost a thousand days old... that sort of thing almost never happens elsewhere.]</p>

<p>[In addition, similar questions that are not exact duplicates can be linked (both via links mentioned in comments and in the "Related" column in the sidebar) to help users find additional useful information related to their problem.]</p>

<p>As a result, it's actually important to avoid answering duplicate questions, so that good answers are not all over the place but concentrated into as few locations as they reasonably can be.</p>

<p>This different way of organizing a site requires a different kind of effort -- in place of answering every question, we end up spending time in so-called <em>curation</em> -- closing duplicates, improving old questions and answers, finding previously missed duplicates and closing them/linking them to answered versions of the same question, and so on. But the end result is far better -- new users, instead of waiting to get a question answered, can find their question <em>already answered</em> and typically in better fashion than they'd have got if the site allowed duplicates.</p>

<p>This benefit happens even if they have never heard of StackExchange, because good answers here show up very high on search engines like Google.</p>

<p>Indeed I have noticed more and more over the last four years or so that searches for something stats-related that I type into Google have links to answers here -- and often they're quite useful. That doesn't happen with my old answers on other forums (at least hardly ever) -- even when I type a search specifically designed to locate an old answer I'm looking for.</p>

<p>But let's imagine that we could marshal some argument for only allowing users with low reputation / recently-created accounts to ask duplicate questions (which are still otherwise deliberately not allowed, following network policy), in spite of the fact that new users will be the main source of duplicates. </p>

<p>If we did that, then <em>any</em> user who desired to get around the policy could post duplicate questions by simply creating another account, so duplicates would proliferate even more. We might as well toss out the entire SE model .... and in that case, I'd be saying my goodbyes. I don't need to participate in still more forums that encourage us to ignore previous good answers. I've done that already.</p>

<hr>

<p>$^\dagger$ why do we keep old duplicates around long after the person that posted them has moved on? Because they ask their questions-with-the-same-answers in somewhat different ways, and so different versions of such questions are found by searches. They widen the net of searches that can be pointed to the same good answers -- they do the job of funneling people to where they can get their questions answered without anyone writing a new answer.</p>
