Because you don't have a preposition here.
"folgen auf" would indeed need accussative, since it's a direction and not a location. But without a two-way preposition, the object you follow is in dative.
Also, "no movement" is a strange way to interpret movemen verbs. I always recommend the distinction:
direction = accussative
location = dative
You can move but stay at the same (described) location, that's what dative is for.