Totally agree.
My example from personal experience is based on a logic board failure and now on the new rMBP the SSD and RAM would be binned. But as you say if the SSD or RAM fails the whole logic board needs replacing as well.
I see this as incredibly wasteful by apple, with no positives for the end user.
Apple make a big deal about their eco friendly "green" server centres, stores, mothership etc.
Yet they are quite happy to bin RAM and SSDs that are may not be broken due to soldering the components, that shouldn't be soldered in the first place.
From all the computers I have owned in my many years, ram has failed the most, also why Apple has made it one of the last parts to be interchangeable.
These are soldered components that by their nature have limited lifespans......while they maybe long, we know for a fact they will die. I have a 2005 powerbook , works, replaced ram, replaced HDD..... lets see how reliable my 2016 machine is....first fault it gets replaced....