In two consecutive books, God inspired these writers to actually pump up this generation, give them good marks because it says they served the Lord. We know they did not do perfectly; they did not complete things totally. But maybe four stars, right? They did most of what God wanted them to do, and He was satisfied with them.
That is what He wants to see, but the Israelites of that generation, He could not do anything with them. So we want Him to be pleased, not angry. And what we get from the end of Joshua and the beginning of Judges was that He was actually pleased with the next generation because they knew the Lord and they did what the Lord said.