Volunteers from civilised countries go to squalid countries to help provide services the locals could do themselves. Some are drivers, cleaners, nurses or doctors. They would do more good working the same number of days at home and quietly donating to charities to pay locals to do the work in the squalid countries. They could also donate their air fare.
Rather than this more effective way of assisting they want to go and work in the squalor. This ostentatious display gives them kudos amongst their friends, "look at moi, look at moi". It also appeals to the vanity of their rich self importance amongst the natives.
Usually this vanity is harmless costing their civilised homeland only the cost of extricating them from their foolhardy exploits. In the case of Ebola the cost of their foolish vanity is to put the rest of their countrymen at a risk they didn't volunteer for.
If these people want to go that's their concern but they shouldn't be allowed home until after a period of quarantine.
