In Bishop Camara’s case, they might have been calling him a communist because he was an open socialist who advocated Liberation Theology. But leaving the specific case aside, let’s speak more generally: the problem isn’t that people think it’s inherently communist to wonder why there are poor people; the problem is that you are asking the wrong question.
The state that we now call “poor” was the default condition of the vast, overwhelming majority of humans for the entirety of our existence on this planet. Agriculture has only existed for 10,000 of humanity’s 200,000 years; the vast majority of your ancestors were hunter-gatherers with no more wealth to their names than what they could comfortably carry on their backs or construct in a few hours’ time out of grass and sticks. A modern guy living out of his car has more wealth than our ancestors did.
The important question is not why most of the world’s people are still poor. The question is why some of the world’s people (or groups of people) have become fabulously wealthy, and if whatever they did can work for everyone else.
Why are people poor?
Why shouldn’t they be poor?
You want to be rich? Figure out how the rich did it.
Quality of life and human well-being have increased tremendously around the world in the past 30 years. The number of people suffering starvation has dropped precipitously. Why? Did Ethiopia and China introduce some fabulous new welfare program to provide for their poorest citizens? No. Capitalism and technological advances in food production happened. (Caveat: Russia post-USSR had collapsing well-being due to, AFAIK, terribly managed and opportunistic transition to capitalism. As always, don’t be stupid.)
Before you can make solve problems, you have to understand what the problems actually are–and that requires asking the correct questions in the first place.
Second, you have to answer the question properly.