Narrated Abu Jamra:
I asked Ibn Abbas (radiallaahu `anhu) about Hajj-at-Tamattu’. He ordered me to perform it. I asked him about the Hadi (sacrifice). He said, “You have to slaughter a camel, a cow or a sheep, or you may share the Hadi with the others.” It seemed that some people disliked it (Hajj-at-Tamattu). I slept and dreamt as if a person was announcing: “Hajj Mabrur and accepted Mut’ah (Hajj-At-Tamattu’)” I went to Ibn Abbas (radiallaahu `anhu) and narrated it to him. He said, “Allah is Greater. (That was) the tradition of Abu Al-Qasim (i.e. Prophet (sallallaahu `alayhi wasallam)). Narrated Shu’ba that the call in the dream was. “An accepted ‘Umra and Hajj-Mabrur. “
So Ibn `Abbas (radiallaahu `anhu) ordered Abu Jamra (the narrator) to perform Hajj Tamattu`, even though some of the companions used to advise against it. Abu Jamra did perform Tamattu` and saw his dream in which he was told his Hajj was accepted. When he told this to Ibn `Abbas (radiallaahu `anhu), he affirmed it by saying that Prophet (sallallaahu `alayhi wasallam) preferred Tamattu` as well.
Lesson: people may have their opinions and reasons, and they may be very genuine. But when you know the opinion and preference of the Prophet (sallallaahu `alayhi wasallam), just go with it!