My honest question is, why those writers should be any different?
So I am also an engineer. Products that I have developed/contributed to development are used by millions of people. (I'm being a bit cheeky here by copying you, but this is true of me too.)
The compensation packages of engineers are wildly different than that of writers because our jobs are steady.
The compensation structure of writers is designed to carry them between shows when they are not making any money. They also need excess cash to fund retirement savings, insurance, and other benefits because they are unemployed for long and unpredictable stretches.
The residuals system was designed to address this very specific structure of the writing profession. As engineers, we don't have these wildly unsteady employment schedules, so the residuals system is not warranted in our profession.
Your experience as an engineer/scientist is valid, but you have to understand how wildly different writing is as a career path, and how compensation packages are different out of necessity.
And no, I do not think that argument "but it is difficult work, it is not constant" works here. There are lots of difficult, non-constant, seasonal, whatever jobs there that pay even less.
Sure, industries like retail, tourism, and food service have similar weaknesses, but those industries are unskilled. Writing is highly skilled labor. WGA members are responsible for writing the most valuable media on the planet, American film and television.
The distinction between writing and these other industries can be measured in dollars.