It's not like this initiative disallows you from building other high speed rail connections.

It does though, raillines cost money and money is finite.

When you build poorly planned highspeed lines any new line you want to build after that is going to be underutilized. Underutilized raillines will be (and have been) scrapped, which makes certain areas even less reachable by train

I think a Rome-Berlin line makes somewhat sense, due to the south-west - north-east coverage you get. But Amsterdam-Berlin does nothing more than isolating the North of both the Netherlands and Germany even further