I can completely understand the desire to remove people who aren't paying attention to you as much as they used to. It feels like "what's the point of any of them sticking around?" and sort of "mentally unfriend" them before even removing them. For me personally though, I've always been very afraid to remove people from my actual friend lists for fear of being **** talked behind my back (it's how I've managed to keep emotionally abusive people around in my life too). I need to stop being so concerned with how people view me, but it's been a big struggle for years.