You don't just drop someone without presentation experience onto a stage in front of hundreds or thousands with a laptop and a projector. That's a great way to get negative reviews for the conference from the attendees.
Much like you don't hire someone with no experience writing software to come in a write you a brand new point-of-sale system for your chain of a thousand stores just because they're enthusiastic.
I think you're making an assumption that I disagree with the conclusion of the article when in reality, I don't. My initial reaction was that it was overly exclusive and in a way, it is. They don't give a chance to those with no experience doing this kind of thing, which makes the bar for someone with no experience that much higher.
However, I don't think this is wrong, especially for such a large conference. If this were a smaller conference then I think it would actually be overzealous, but that is not what I think in this case, which is why I said it was only my initial reaction.
I would also like to add that the example summary given shows more than just enthusiasm, it shows knowledge of topic as well as the ability to convey that information in a concise and reasonable way. So, a more apt comparison would be not hiring said person to build your brand new POS system just because their academics were good and make a nice resume (just without job experience).
Much like you don't hire someone with no experience writing software to come in a write you a brand new point-of-sale system for your chain of a thousand stores just because they're enthusiastic.