Not so...

Some Performance hybrids can approach the speeds of their drop bar road bike rivals. Many other hybrids come equipped with wider wheels and tires. They're quite capable of not only serving best as commuters, but light off road duty, as well. Some, like the Marin Muirwoods, are quite up to the task of doing mild single tracking, as well as some credit card touring to boot. That's in addition to serving as a commuter.

Therefore, I've found that at opposite ends of the spectrum, bikes do specific things very proficiently. However, the hybrid tends to hover about the middle of the spectrum. It can usually perform most tasks that either bike at the opposite ends can achieve, but just not quite as well. The Muirwoods beats a race road bike, with the need to cycle upon a gravelly road. The Performance hybrid beats a mountain bike, when the need for speed on a nicely paved road is required. That goes double for a mtb with full suspension!

So yeah, hybrids can do it all!

...Up to a point!