If you cover all of Austria from west to east, coming from Munich to Austria, it is almost inevitable to go through Linz. However, the fact is this small city doesn't have much to offer unless you want to rest or sleep. It is a fairly quiet town, with little movement. The walk along the main street that leads to the shopping plaza is nice as it is right next to the river. As I said, the place is nice and not bad, but from my point of view you should not make it a basic point of passage for a route.