"Speech about people must be with knowledge and justice, not with ignorance and injustice..." - Ibn Taymiyyah (Rahimullaah)
I personally believe that mankind, by design, has a good heart. It is our fitrah. And it is out of love for one's Ummah, for the sake of Allah SWT, that a piece of advice, gentle reminder or a friendly nudge was given when one sees something 'amiss' from one's perspective. Nonetheless, the intent is always good but sometimes the approach may be unsuitable for the situation or context.
Truly, it takes hikmah (wisdom: putting things in its proper place i.e. Adab) to do da'wah. In essence, before one speaks, ensure one must be equipped with Ilm' (knowledge). Know when to speak and when to be silent. Know how to speak and to whom one should speak.
Afternote: I don't understand the 'labelling culture' of calling someone salafi or wahhabi, etc. Always bear in mind Satan's determined whispers to break the Ummah. Mum's constant reminder stays with me - that we should always see the good in people because that was how our beloved Prophet SAW treated people of all walks of life, race or religion. Indeed, his mercy and compassion for humankind was beyond compare.