Why not?
They are rich and can afford it. They believe in crypto. They decided to support people from more needed regions.
If I remember correctly, Dorsey took time off Twitter a year or two ago to spend time in Africa and help the local startups. I guess this is the second round.
It is also worth noting that this help is a big benefit for them because they are going to be using this for their tax write offs. And I think that it is a good initiative that people of their status are using their power to influence good things to happen to the people and to the cryptocurrency community as a whole. Never heard of this story about Dorsey going to support start ups, I guess investing in people is a good thing for business and since you are on the top, you have to do everything you need to stay there.