Without Philipson to contest the sprints he's been doing everything he can to attack and get and stay in Yellow for as long as possible (until today & start of mountains). It's also just his way of riding (aggressive, powerful, never say die). In the mountains and without a big GC star in Alpecin, he'll be on survival mode until the next rolling stages but if he sees a gap, an opportunity, he'll always go for it.
I mean he's cycling royalty with his Dad Andri a huge Classics & Cyclocross star in the 80s (Big rival of Sean Kelly's, used to frequently shove each other into the barriers in sprints) and his Grandfather the legendary Raymond Poulidor, 3 times second in the Tour and 5 times third, but never won, the French favourite, Pou Pou the eternal underdog.
MVDP is such a character, media love him and he's great with them too. When he did his first Giro, the Italian journos flocked to see this "northern' legend, the whole of Italy was curious. And he had such banter with the Italian press. Of course they asked him his favourite pizza and being Dutch he told them he loved ham and pineapple shocking the appalled Italian public and journalists (which I'm sure MVDP got a big kick out of). Then after racing his heart out in typical fashion and being in pink for several days, at the end of the final stage he'd become an Italian favourite, the Tifosi taking him to their hearts. The Italian journalists presented MVDP with a pizza - a ham and pineapple pizza.
Cycling dynasty, from top: Raymond Poulidor, Andri Van Der Poel, 3 generations together.