They are simply responding to market demand, that's what companies do.

The more pertinent question might be, why is there a demand for "fast"
80mm
refractors? My demand for a small refractor had to do with compensating
for
a large scope that was difficult to manage in and out of the house Couple
that to the fact that a fast 80mm provides fields of view that compare
favorably with binoculars, and you have a compelling solution.


Companies also and more often provide what they want to provide making
choice
restricted. I highly doubt the major scope companies do significant market
research
to nail down the 80mm solution