I've now seen tons of complaints about the viral show of support for Paris while the media and most people have been almost completely silent about a similar attack just one day prior in Beirut, and months before in Kenya. I wouldn't have even known about the attack in Beirut if I didn't read about it from someone who lives there.
Most Westerners don't have a degree in international studies. Unless you have a specific reason to hold specific knowledge about a specific country, most of the Middle East is viewed under a single umbrella as one big scary land full of psychos. The internal struggles and violence within the umbrella of "the Middle East" seems distant, and there's no surprise when it happens because that's what always happens within a group of tribalistic and violent cultures.
It's not that nobody "cares" - it's just that everybody is resigned to the inevitability of the constant cycle of violence. All sense of "caring" what happens "over there" is stripped away by unfamiliarity and desensitization. But when the evil and violence of radical religion spreads into the relatively peaceful and stable Western world, that's new. That provokes a response.
Imagine a pin pricking the same spot on your hand for a decade. The wound bleeds, it scabs, and eventually it grows calloused and no longer hurts after a while. It doesn't bother you any more. Now imagine it suddenly pricks your other hand. You feel that. That's a fresh wound.
It's not racism or hypocrisy. It's desensitization, resignation to the inevitable, and simple ignorance of the finer details in a gigantic world that can only be understood through generalizations.