This is a bit outside the topic of this sub, since why people today choose to talk about something isn't a question about history. It's a question about modern day attitudes.

But one reason that the Atlantic slave trade is a relatively popular subject in the modern public awareness is that it was fairly recent and had a significant impact on the development of several first-world nations. It ties neatly into a lot of other historical subjects which are widely considered important, like the industrial revolution, the discovery, colonisation and eventual independence of the new world, etc.

This might be a question for r/asksocialscience. The Atlantic slave trade has been used for political and social gains whereas the Arab slave trade is of no concern to Westerners. Why don't people mention the Irish slave trade? Because it does not fit into the agenda and/or narrative that is going on in, primarily, the United States. I'm anxious to hear a better answer than mine because this is an interesting question. Take my two cents with a grain of salt.

This submission has been removed because it violates our '20-Year Rule'. To discourage off-topic discussions of current events, questions, answers and all other comments must be confined to events that happened 20 years ago or more.