gatewalker, good question! Those in the professions you mention, have to pass assessment prior to being able to charge. Hence, they aren't charging for their natural aptitude, they are charging for the qualifications, which enable them to use their gifts to help people in a professional capacity.
Others have 'gifts' yet don't need to pass qualifications in order to charge. Musicians and artists, for example. However, musicians and artists are unlikely to cause customers or potential customers significant harm, if they produce work of substandard quality.
When people pay, they need the results to validate their expenditure. If someone gifted charges, their 'customer' is more bound to believing what they've been told, no matter the detriment to them, as with OPs friend.
So, I don't believe 'gifted' people should charge, not because I believe they don't have a right to earn a living but because it places 'customers' at risk of psychological harm, because there is no sure fire way for the average (often vulnerable) customer, to decipher charlatans from gifted people.