Of course I expected my video to elicit some negative comments, but I was surprised to see almost *only* negative comments.
Well, EEVblog (and its forums) is famous for blunt honesty.
Surprised, because this is a good method, and one that I see no negative downsides to.
But there
are downsides.
The advantages I mention (assembly speed, better contact area, smooth result, protection from oxidation, reduced shock stress), are all true.
Speed? Debatable. If you really care about assembly speed, you buy those special pliers that cut and clinch the lead in a single squeeze.
Smoothness? Yes, it's smoother, but what's the advantage of this? I can only see this mattering in wearables, where cut ends snag on fabric. In a typical electronics application where the PCB is in a housing, it's totally irrelevant.
Protection from oxidation? Absolutely irrelevant. If your board needs protection from oxidation of the cut lead ends, it needs protection of other areas, too, in which case you use proper protection like conformal coating.
Reduced shock stress? If you're using proper, sharp tools, this really is a non-issue.
In the video, you also keep mentioning copper-to-copper contact, as if solder somehow produced so much resistance as to matter. It doesn't. If it did, then millions (billions?) of devices that use DIP ICs would be malfunctioning, since DIP ICs are not normally clinched in mass production (in contrast with things like resistors, whose leads are normally cut and clinched by automatic inserters).
Some comments indicate that I may not have gotten my point across clearly, for example that the lead barely protrudes past the hole and/or that the lead is buried under a blob of solder and thus good contact with the solder cannot be assured. No, there is ample lead exposed to the solder, and an observable solder fillet, indicating good wetting, is formed:-

Your joints would fail IPC inspection because the component lead is not identifiable in the solder mound. It should be a meniscus, but leaving the lead shape visible.
On the subject of removability, the video shows how easily I removed the resistors soldered in what I termed the "bad way". Not to mention, the part being removed is likely suspect anyway, and causing damage to remove it (if required) should not be a problem, especially for cheap parts like resistors.
It's not about damage to the component, normally. It's the risk of PCB damage. With a resistor it's easy to get around, but what if you've clinched the leads on, say, a large electrolytic capacitor? You cannot snip the leads before desoldering, since they're hidden. So you must desolder first, and then while the solder is molten, pry up the clinched leads. Such mechanical stress on a hot trace is riskier, since the bond strength of trace to PCB is reduced while hot.
I concede that the video title may be somewhat misleading and presumptuous (though not actually incorrect) and will change it to "An alternative method for soldering through-hole components". (and the subject/title of this thread also)
No, it IS incorrect to imply that the standard method is "bad" and "poor". And the new title is differently wrong, insofar as it's not an "alternative" method — we've already demonstrated to you that clinching leads is an established method.
To the criticisms relating to the more general aspects of video production (length, quality, etc), I say "Let he who makes perfect YouTube videos cast the first..."
Ah yes, the classic "well let's see you do it better!" retort… Me, I haven't bothered making any soldering videos because even if I had the equipment for and experience in video production, I couldn't exceed what PACE has already done.
But also, your video is 15 minutes long, but could be edited down to probably 3. Meanwhile, it doesn't cover so many other important steps in soldering, such that it can't by any stretch of the imagination be considered a tutorial on soldering THT. It's merely a video about lead clinching. In 15 minutes, one could actually cover a lot. But again, why bother, when PACE has already done it so well?
The PACE soldering videos mentioned above are indeed excellent. In places their examples have clinched leads as I advocate, though I cut them shorter than they show (which would make removal easier).
So then your method is actually one of combining the downsides of both standard methods? Either don't clinch, or do it properly (since the only real advantage is one of vibration resistance for high reliability in high-vibration environments).
And finally, I say "don't knock it 'till you've tried it".
Almost everyone will have a never-to-be-used PCB lying around, and be able to sacrifice a dozen resistors for science.
Please try out what I've described, and see if I'm full of crap...
I think it's rather presumptuous of you to assume that we
haven't ever tried it.
Your attitude is one of "look at me, I know the one true way, nobody else does it like this but I know better, and everyone else would see the light if only they'd follow my lead", when in fact it's not secret knowledge, it's an established way that is used in some situations, but also isn't a magic panacea.