Selfless tears?

I've read a post on a blog in which the author states that she doesn't think a person's death is really something sad.

She considers that someone who cries over somebody else's death is actually selfish, and that his mourning isn't caused by the fact that the deceased won't be able to enjoy life anymore, but actually by the fact that he, the mourner, won't be able to enjoy life with the dead person.

I disagree.

My first question is: "Doesn't that make all of us selfish?". Doesn't that mean that each and every one of us (who surely has or will eventually cry for someone dear who passed away) is selfish? Well, wouldn't that imply that selfishness is a universal condition, albeit only in a certain measure? Sad.

Say I'm reading a book. I don't think that the fact that I cry over the death of a fictional character, just because I've grown attached to it and am sad to see such an interesting (fictional) life end, is selfish.

The simple fact that people I haven't met in my entire life whose life suddenly (or not so suddenly) ends are able to impress me, or anybody for that matter, makes me think that not all grieving is selfish.

On the other hand, I believe the cause of people considering other people's death sad could be fear. The fact that a life can end so abruptly is, indeed, very scary. It makes you really realize that life is very damn fragile. Perhaps this is one of the reasons that makes us cry, the fact that we realize we could be next.

I'll give you another example: have you ever seen Avril Lavigne's video for her song "When you're gone"? Do you know the part, near the end, when the old man is all dressed up, with a glass of champagne in his hand and another one on his deceased wife's tombstone, and says: 'I miss you...'? If you haven't, you can do at the end of this post.
You can't tell me that it doesn't affect you, even if only a bit.

Well, how can you say that someone's death can't be a sad event after seeing that man, reduced to a small child inside, crying his eyes out over a person he probably loved his entire life? If you call that egoism, then egoism is either a good thing, or it's just universal, or both.

(by the way, Youtube doesn't allow me to embed the video from their site, so...)

Avril Lavigne - When You're Gone