As the saying goes, one man’s garbage is another man’s treasure. So don’t be so judgmental. :)
I consume as much as I can but only because the society lets me, and I'm too burdened at the moment to actively change my way of life.
Maybe have some sympathy for others? If you feel so strongly and yet don't change your actions, I think it's pretty hypocritical to say other people are consuming a bunch of "crap". Don't get me wrong, there is a ton of waste produced in today's world and more of it than we need. But I think it's important to consider that many people struggle to make ends meet and can't afford the time, money or thinking that many of us here have.
We both agree that the western society consumes too much, and in the part of my comment which you extracted I included myself explicitly in the group of people who consume too much. I am having sympathy for people who consume too much and don't change their ways. I'm the first person I have sympathy for in this as I'm preoccupied by other stuff than my lifestyle choices at the moment.
I did not denigrate the people who consume too much, merely the habit of consumption.
The actor and the behavior are two different things. Merely behaving in a bad way does not make the person bad. It merely means they have something to improve in their personal conduct.
Calling stuff people consume "crap" is not the same thing as insulting people. Although, western commercialism has done a great effort in trying to tie persons self worth to their consumer habits.
This psychological link is also crap.
But often turns minds of droves of Humans to shit, and turns every moment of idle human thought into raw material....
So, how would you employ the engineers instead?
Industrial society is about producing garbage for the masses to consume. The huge churn of capital and labor creates as it's byproducts from time to time items of actual human value.
But those things would be fragile and complicated without the industrial economy surrounding them. If we look at this stage in our species history from far away, currently the industrial economy is supposed to be predictable and mundane.
So, "producing useless crap" is a required feature of our economy so it can occasionally produce science, art, medicine and the other things that actually improve us as a species.
Now, consumer goods fall into two categories: physical and digital. Physical consumer society is turning our biosphere to shit. Digital commodities, on the other hand, are much more lenient on the environment.
So, if we look at it this way, and presume that producing consumer crap is necessary for economic growth and stability, it's much better to work in producing digital goods and services rather than physical ones.
Within this framework, the actual question is not why do the brightest minds work at facebooks, but, will our economy ever develop beyond the point where producing useless crap is not so much a necessity for systemic stability rather than an occasional indulgence.