Obama was talking to a Greek audience and called out that people were more interested in the Titan. Had he been speaking to a North American audience he would have likely called out the lack of attention on the Southern border. The reality is that Obama is speaking to the audience.
The other issue is that the Titan is overwhelmingly unique. And that makes it news worthy. Right or wrong, when something is common we stop paying attention. So the problem is not that we were interested in the Titan trajecty, but that we lost interest in the migrant crisis for Europe and the US. The problem is that for most, they don't know. The injustice is not in the fact that billionaires died, but that the uniqueness of how the billionaires died caught our attention.