The geo-processing tool Point To Line is a python script tool found in the Data Management > Features toolset. As it is a script one is able to look at the source code. I notice that the code was developed using the older slower cursors. This less efficient code still persists in 10.4.1.
So my idea is that ESRI upgrade the code by replacing the current older slower forms of cursors with the cursors from the da module. Even ESRI say you should be using those as they are faster and more efficient! The upgrade should be for future versions of ArcMap (10.5 onwards) so as to not break the tool for users stuck with older versions of ArcMap.