It doesn't matter how eloquent and thorough the introductory tutorial is, if the presenter has not experienced the technology sufficiently to have accumulated a few scars[1], they will not have the ability to convey the relative importance of the various aspects of the introduction, with which can be modified simply as a matter of taste, and which should be followed unless very careful consideration of global engineering context, and a full appreciation of the consequences.
If you are unable to meet that bar, at the very least, your abstract should make that abundantly clear out of respect for your audience.
[1] or at least have the experience to say that normally they would have expected to get bitten by something by their point in usage, but the technology meets their requirements so thoroughly that it has been particularly smooth sailing.
For example I currently mostly work with Go, and if I would give a high-level presentation about Go I'd start with the "tour of Go" tutorial, but I'd also add some context to some things, explain where you need to be careful to avoid problems, and emphasize the usefulness of other things that may not be obvious at a glance. That kind of stuff. I think the presentation format is a great way for doing that.
A beginning JavaScript programmer might explain the "with" keyword, which would be a mistake. I have no idea if the presentation contained any mistakes like that.
I don't work much with JS, and I haven't looked much as TypeScript since, but I didn't really learn all that much more than what I already knew: "TypeScript is JavaScript with optional typing".
Was it useful for others? Maybe; I hope so. But for me personally I consider it a wasted hour in my life.
Is this not true of most tech meetups / tech conferences though? I feel like they all carry an implicit YMMV with them, which attendees know when deciding to join.
To you. On the flip side, it provided an introductory level overview of a concept many watching/attending may not have looked into themselves, or were thinking of looking into. It also provided a different form of introduction, which could be valuable for attendees with a learning style preference different to that of look-at-a-how-to or check-out-the-docs.
>the guy replied with "well, actually, we haven't really used it yet, we're just looking at it".
Hey, at least he was honest and didn't try to bluff his way through an answer, as many in our industry will.
Overall, depending on the audience and context, it sounds like it may have been worthwhile for many attendees. Plus he got to work on his soft skills, and doing so with such vulnerability could inspire others to also.