Stars more massive than the Sun have higher core temperatures. Nuclear fusion rates increase dramatically at high temperatures (eventually though a different mechanism, the carbon - nitrogen - oxygen cycle).
Thus the more massive the star, the greater the luminosity.

Massive stars burn through their nuclear fuel at a much faster rate than low mass stars, and, consequently, their lifetimes are shorter. For example (solar units and millions of years):

In order for life to develop, the central star in a planetary system must be long-lived: this restricts the sample to stars with masses less than 1.5 times the Sun's mass (but not too small).

Fortunately such stars are the majority in the sky.