"I can imagine him trying to explain to a layperson"

Its a 2011. Trying to sell that in, lets say, 2019, it'll sound a lot like when I sold my 1997 Saturn in 2013 with a hole for a ham radio antenna, in other words it'll be so old no one will care. Also they were more interested in the cracked heater core, broken sunroof opener, leaking sunroof, worn out brakes, and high oil consumption, than being worried about a little hole.

If I were the OP i would sell his "speed enhanced" laptop right after this operation. He mentions having to heat mainboard in the oven. Actually this operation doesn't work for any long term period and during each heating session he risks frying some other components on the board.

"They increase the airflow, making the computer never overheat and die"

It's not that hard to understand.

"But they are ugly and now everyone is teasing me about them. I want a refund"

They're literally speed holes.

They're really not. "Speed holes" by definition make something go faster. In this case, it was done to help the temperature. Not to overclock.

They prevent it going slower.

They are neither red nor blue, disproving your statement.

I would have at least put some sort of screen or filter over those holes.