Is this not every christian persons responsibility? Why do you elevate a paid christian over an unpaid christian?
Because hobbyists are not professionals. Professionals have more detailed responsibilities and are held accountable by other people, and if they don't measure up, can be without money to pay the rent—not only next month, but also for the next several years.
They do not have the luxury of doing what they want, they must do what they believe is best and it also must meets the approval of other authoritative people right then and there, some who know more and have more experience as well as some who
think they know more and have better experience. It means they need prior training in what other people will expect of them so that they can handle it when it is unloaded on them.
Professionals have standards that they must meet, and have to deal with people who think the pro should meet a fantastical standard that only exists in the judgmental person's mind. Professionals are forced to make decisions that will affect people's lives—who they then must be nice to every week.
Professionals have far more interactions with people, which results in a larger weight (or oppression) of always having to say and do what is exactly right, and in practice, has to smile and accept a cargo of complaints, criticisms, and (hopefully not too many) insults that come back—which they can't dismiss or ignore, but actually have to deal with as a Godly adult. People look at them and expect them to be like God.
Professionals recognize they they no longer just represent themselves, but they represent their organization. They have different responsibilities because of that and must speak and behave differently to accommodate it. Professionals can often not take a break even when they are getting overwhelmed with work or life. How important your cousin's overseas funeral is changes when you're also responsible for the well-being of a hundred or a thousand other people (It's a good thing the professional minister doesn't also have to feed them and change their diapers, except that sometimes they do actually have to be mom, even though it's not in the job description.)
People that love their hobby so much they want to do it all the time often try to turn it into a business. Most discover that it's completely different (especially for those that want to do the best job possible in their business). No longer do they get to do what they want, they have to do what pleases the people at the same time as doing what the people actually need, otherwise people take their business elsewhere, because there are these things called competition, personal preference, and being overly sensitive or zealous about silly things.
Thank you Lord, for doctors, other emergency services professionals, ministers, and the people who fix my furnace when it is below freezing outside. I'm glad it's not something they just do when they feel like it or only when it is received with thanksgiving.