None of the forefathers quit their business or farms in some concept of "conflict of interest" to serve as president. We don't require it of other govt officials and I don't see it as necessary for office of President either. In fact, one could point to Bill and Hillary's enrichment scheme using a questionable charity foundation as their "conflict of interest" while she was serving as Secretary of State. Where was the call for them to divest themselves of that to avoid "conflict of interest"? If whatever Trump does helps some business interest he has, so long as it's open and fair and others may also benefit from it, I see no conflict.