Writers, Books and Publishers' limits (a rant)

The other day, I was visitng the site of a Guyanese writer I love, Sharon Maas, and I was surprised to see that her publisher refused three of her novels. The main reason being they were about Guyanese characters in Guyana, so nobody would possibly care about it. I was shocked. She has three other novels published (the third one is missing on my bookshelf). The first one was between India, UK and Guyana, the second one between Guyana and India... so I thought the reason for the latter novels not being published just absurd.
As a traveller since my birth, I love to hear about other places, other cultures and traditions. As a reader, I love to travel with other people's words. And as a writer, I would love to talk about my own upbringing meaning that I would more likely talk about Angola at some point. But just like Guyana, I can already hear that "who actually cares about Angola besides Angolans ?"
I think this is very sad and prejudiced. Sharon Maas has sold books around the world, and yet she doesn't have the right to write about her own country or she has to find another publisher who won't shut her freedom of creation off.
Haven't publishers heard we were in a era of globalization and low cost flights and people didn't focus on their homeland only ?! It just leaves us travellers/nomades/gypsies/expats/you-name-it with less literature that could remind us of ourselves...

Okay, ranting over ;-)