The Layer To KML tool in ArcGIS Pro 1.4.1 creates a bad KMZ file if the input feature class is a line feature class that is not in the WGS 1984 coordinate system.
Duplicate of BUG-000102721: This has been fixed in 2.0 as:
BUG-000102721 - KML files created using the Layer to KML tool in ArcGIS Pro 1.4 do not display correctly if input data is not in WGS84 (WKID: 4326).
解决办法
Reproject the data to the WGS 84 coordinate system beforehand.