They are found only because they are close, leading to a quicker orbit, and therefore surveyable with current technique of spotting a planet occulting its primary, with Earth viewing the passage from the observed star's ecliptic. Like diamonds found laying on an open plain, or meteors discovered in the eindless white of the Antarctic, the easy ones are found first. The rest take time -- and sientists hate time. Depending upon a star's attitude, her treasures may yet remain hidden from view -- and may remain so for decades, even centuries to come.

In time, the more distant Jovans orbiting stars whose ecliptic is aligned with Earth would become visible with today's technologies, merely because the time passed that would allow occultation and detection. We won't wait for this, of course, and will eventually raise a technology that will find the little rebels to the laws of statistics -- the exceptions to the rules. And some of these habitable planets might orbit stars lacking detectable Jovans.

No conclusions yet, but a fun ride nonetheless,
Dan