You asked:
"If something has the ability to increase your self-worth, self-esteem, self-respect, confidence, does it not also result in an enhancement of your spirit?"

Of course. Presenting arguments showing the benefits of learning an indigenous African language, together with evidence of successes from so doing, would encourage more Africans in the Diaspora to learn an indigenous African language. The African language they choose to learn would depend on where they feel they will get the most benefits. But any indigenous language learnt can be a benefit.

The point that I was making is that generally speaking, people will learn different languages if they feel their survival depended on it or if they feel it can enhance their economic opportunities. In the Caribbean, for example, there is not much trade with Africa, and so, many will not see the relevance of learning an African language to enhance their economic opportunities. The little trade that is done with the Continent is already done in an European language.

In my experience, most Africans do not see the value in something until some leading European says it is valuable. That is part of the colonial conditioning.