Perhaps it is BS and for sure in a 30 car pile up, there is not one single cause or one single accident to investigate, but many possible causes in 30 individual accidents. But as for speed in zero visibility - are you really suggesting that you should be driving with your eyes shut? If not, how much faster do you think you should you be going than the distance you can safely see to stop in?
I need to be very careful here. Last time I 'contributed' (for small values of contribute) to a 'driving' thread I said how I was unsympathetic to anyone who speeds before the speed limit terminators. I still am[*1], but naturally Karma Kamera then clocked me at 34 in a 30, 20 yards before the terminators and I spent half a day last week attending a speed awareness course. Part of that involved a video analysis of another motorway pileup - the 1991 M4 crash. The video was a reconstruction using toy cars - just documenting what happened from the van hitting the central barrier to the last cars impacting the mayhem. The chap who was taking the course gave a simultaneous commentary of the footage - the whole thing lasted 5 minutes to describe in amazing detail what actually took 19 seconds. Much of that carnage was due to people driving ... not over the speed limit, but too fast for the conditions and too close to the vehicle in front. It's difficult to see in major multi vehicle pileups how anyone but perhaps the unfortunate first vehicle can claim anything else. When you plough into the back of something, you have very few reasonable excuses.
[*1] Perhaps more so.

