Oberon, I am one of those queer-minded old-fashioned people who switch their computer off when not using it.
I also do not tolerate software environments full automatically downloading and changing my system, not even Windows Update. I supervise Windows Update manually, and as far as I am aware of it, all other stuff as well.
And finally you did not get the point: having your system downloading such volumes of data at speeds like that, blocks the web access and de facto locks you out from using your computer for whatever a purpose. For hours. For the evening. For the night. For the whole damn day, and if you are lucky: for longer. And if the download messes up, it all starts again from the starting line. Thats why you better do not touch it when it does downloads like that... Has all happened for me, I talk by experience. Nothing beats a 123 hour download of 10 GB of data - and when the progress bar is at 96% the whole thing freezes becasue you opened free Mail to send an email, or you open the browser but the website bogs down. Priceless... I hate Steam and DLC business models.
BTW, for some reason Steam servers do not transport stuff to my part of the internet (where I use Skyrim, Assetto Corsa) at higher speeds than just ~1500 kbit/sec, that is half the speed I could get at maximum with my DSL link. So with Steam things become even worse, regarding downloads. They last twice as long.