I think most people do worry about the affect it might have on those left behind. Honestly, I feel a bit puzzled by people who don't- but- maybe it's because those same people have been the cause of their unhappiness. It maybe depends on how much that person experiences grief and loss themselves. If it doesn't affect them all that much, they may not worry so much about people left behind.
Not sure whether it's egotistic- we are just about to obliterate our egos from the face of the earth! In some ways, it seems more egotistic to believe your death will utterly devatate people's lives. Not to say it won't- it might of course. I once read a post by someone saying their death would be bigger news than the death of the Queen (of England.) Who knows? Maybe they were some big celebrity but- that's quite a big statement to make!
I'd agree that suicide is self absorbed and selfish to some extent. We certainly are putting our own needs first. Still- I'd argue- take a look at this world. We have been encouraged to be this self absorbed to begin with! Plus- take a look at who really gave a shit about them when they were alive. Most people are so wrapped up in their own lives.
We all have to make our own choice at the end of the day. One thing I feel condident about is- any person who has the guts to go through with CTB does it because they simply couldn't cope anymore. They deserve sympathy, not hostility. Chances are, they hated the idea that their suicide would cause pain to others but they simply couldn't cope with their own pain anymore.