I think that there can be much to support this idea. Individuals in both England and the United States drove to stop the practices of the Atlantic Slave Trade because of humanitarian reasons intrinsic to the abolitionist movement. The abolitionist movement was not really driven by economic motives. Rather, the members of the abolitionist movement felt a moral imperative to speak out against the slave trade.
Individuals in England such as Wliberforce were compelled to do what they could to end the Atlantic Slave Trade out of a moral objection to slavery. When he writes in his diary that, "God Almighty has set before me two great objects, the suppression of the slave trade and the Reformation of society," one can see that it is done out of a moral imperative. There is little in the way of economic motives here.
In America, the Quakers, who were such an instrumental part of the abolition of the slave trade and the importation of slaves via the Atlantic, were acting out of a religious frame of reference. It was this emphasis that helped to stop the increase of the slavery institution through importation via the Atlantic. This was a religious moral issue for the abolitionists.
The outlaw on the international trade of slaves was driven by those who were operating from a religious, moral and ethical base of action. It is here where I think that clear understanding can be formed as to how humanitarian reasons and not just economic ones helped to end the Atlantic Slave Trade.