Not really true. A virus that kills the host too quickly is not going to spread. A virus that kills the host quickly but not before it spreads, IS going to spread. There's no saying what a virus 'wants'; they just happen, and they do what they do. If Ebola became airborne, then most of us would die, then Ebola would die (from lack of hosts), and that's just a pity for Ebola. But there's nothing that stops such a scenario from happening, least of all what Ebola 'wants'.
To expound on this point, to a virus or bacteria, a human is just as good as a monkey or dog or jellyfish. It's a place to replicate and live. Similar with viruses as technically they are not alive. All these Dr. Doom kinda things have to compete with the common cold, the e. coli, and all the other things that live on the earth and in your guts. That is not an easy environment to survive in.
