Not really, since there are only a few known instances of asteroids hitting earth in hundreds of millions of years, but climate change is an immediate threat within the next 50. The odds we live to see an asteroid hit us are slim.
Presumably this is based on a belief that humans are likely to go extinct. I don't agree; I think we're extremely unlikely to go extinct and, following from this, an impact is definitely something worth worrying about.
It doesn't even have to be a "planet-killer," a smallish impactor could wipe out a city.