If I am standing on 72nd and Columbus Avenue and want to get to 92nd and West End, there are many, many different ways. One can't say that one path is better than another. The important thing is that the path lead to the destination.
The root of sinas chinam is not appreciating the differing paths in service of Hashem. We often look askance at other people and groups. The tzadikim fix this because they understand how many paths can lead to Hashem. One destination, many paths.
