What kind of pavers? Clay or the roughly 8"x4" interlocking concrete pavers. - The bigger concrete pavers are NOT pavers, but "stepping stones".
The why is based on the fact that the interlocking concrete pavers are the most commonly used by a wide margin and the installation over a compacted base and 1" sand setting bed is by far the most trouble-free method. The high strength (8,000 - 10,000 psi) of the concrete allows the interlock between the paver and ability to be finished off with a vibratory plate compactor. This is why concrete pavers are generally used on used on large installations (up to 40 acres) with heavier loads such as driveways, streets, airport taxiways and industrial facilities.
For a smaller, casual installation in relatively low freeze-thaw conditions gluing down any pavers will work for a while if the adhesive can perform considering the moisture and freezing since the slab underneath prevents the water from draing away underneath.