Unfortunately the article is behind a paywall so I can only look at the three lines in your post.
Looking at those three lines, it is clearly written by someone who has never watched a three week grand tour. The "strange" tempo to which he refers is entirely normal and has been for every grand tour I have watched, and I have been watching since 1984.
The reason you have serene days that end in a sprint is because the terrain doesn't suit a general classification punch up, and the chances of gaining time are pretty insignificant. So all the GC domestiques have the day off and leave it to the sprint teams to catch the breakaway as they are the teams actively targeting the daily prize. This doesn't happen in the mountains as the sprinters shoot out the back as soon as it goes uphill, which leaves a GC scrap, and with more of an opportunity as you can gain minutes on a big mountain stage. So you don't waste energy after maybe a second on a sprint stage.