This, in a machine that's been designed for generations to have a fan pull air aggressively THROUGH a channel, the only path the air can go, that goes directly across the CPU heatsink. This is not a 'circulating the air' situation: a laptop can't do that. It's an overall system with many considerations (turbulence, air handling noise) that is no longer a system at all if you take the top of the duct off. You cannot run that sort of machine with the case taken apart, it's part of the ducting.
Either he's dishonest for effect (and clicks), or he's considerably dumber than a drummer and college dropout (yours truly! derp!) about cooling airflow in a constrained duct inside a laptop. At face value, he's dumber. For his sake I hope he's dishonest.
The design of a modern motherboard is far from complex since all the complexity has pretty much been hidden inside the black boxes of highly integrated circuits. You as a designer do not in general need to concern yourself with the implementation details and just need to understand the interfaces, similar to, for example, using python's numpy as opposed to writing BLAS or LAPACK from scratch.
Getting GHz frequency circuits to work requires much more than just understanding the digital interfaces.
If you think designing and laying out a modern motherboard is “easy”, then there’s a 1% chance that you’re a highly experienced and capable electronic engineer, and a 99% chance that you just have no idea about the existence of entire classes of problems that need to be solved to make a motherboard work.
I am not saying it is trivial or that Rossmann could do it with his knowledge (no, he could not) or that anyone could do it. I just claimed that in the grand scheme of things it is not "highly complex" (as opposed to pretty much anything analog, or proper RF, or getting the actual implementation inside the chips correct).
If you haven’t actually been involved in designing a motherboard yourself, I’m also inclined to believe that there might well be complexities that you’re unaware of. Power management is complex. Routing hundreds of length-matched high frequency traces is complex. Low power circuits are complex. Safely charging LiPo batteries is complex. If you can show me something similarly complex that you’ve done yourself, then I’ll be willing to believe your claim that all of this is not really very difficult.
I have not designed a motherboard, but plenty of smaller digital IC-based schematics and PCBs and in my experience the most problematic part has been either erroneous or lack of proper documentation or bugs in ICs which there are plenty of.
What I recommend you to do is to compare the schematics of, for example, Thinkpad T420 and Keithley 2001 both of which should be available with a search. What you will find is that the former is a collection of specialized chips (including one for battery charging) with mostly datasheet reference design based implementations + bunch of mosfets for enabling/disabling/routing signals, whereas the latter has almost none of that and plenty of analog "cleverness" and "raw" digital design, let alone the power input, which in my opinion was totally overdesigned. Or take any oscilloscope, where you need to design not only a computer but also an analog front-end + high frequency signal processing, not only routing. And I'm not even going into the actual RF board designs which you are probably well aware of is more physics than electronics.
Again I am not saying that it is easy for any guy on the street, but "relatively easy" to understand what is going on on the motherboard as opposed to the actual complex stuff. So if you see a common fault among many motherboards you can probably conclude that that specific area of the design was bad and criticize that. Whether the criticism is valid might be another question, but I would not automatically dismiss it.
Edit: I will put designing a motherboard on my todo list.
Just saying.