The moving walks are to help those who cannot walk long distances. Instead of having a subway, bus or other transport, the airport has decide to use a moving walk. Also used quite frequently in subway systems, such as the London Underground.
In Schiphol, it is well marked that people should stand on the right and walk on the left. In many places such signage does not exist. It’s exactly the same discussion which is for escalators. Or even moving sidewalks
That said, it is mildy annoying when standers decide to block the entire width of the walkway, especially with lots of luggage, which will again be annoying when those same people are filling up the overhead bins.