Reference: Shaykh Ibn ‘Uthaymeen – Kitaabul-‘Ilm
The Shaykh (rahima-hullaah) mentions:
If we carefully consider that which many of the du’aat are upon today, we find some of them are overcome by enthusiasm and as a result cause offence, such that the people have an aversion to their invitation (da’wah).
If they find someone doing something which is haraam, they make such a big thing of it and forcefully say: Don’t you fear Allaah? or something similar to this, such that the person has an aversion to them, and this is not good because this is dealing with the issue in completely the opposite manner to that which is correct.