Anastigmat
Forum Pro
Many reasons
1. poor name recognition due to really small advertising budget and a series of rather undistinguished products in the early 1990's. Canon, Nikon and Sony are household names. Pentax is much less well known.
2. Bad marketing. part I priciing
The *ist D, Pentax's first DSLR, was more expensive than the competition. Yes it is a good camera but pricing is very much a part of marketing. While Nikon was selling the D70 by the truck load, Pentax took a long time to come out with a sub-$1,000 model of its own.
Bad marketing part II Product name
Names are also an important part of marketing.*ist D name is not a good one. Names like Civic, Accord, Sony are much better than names like Mitsubishi or, well, *ist D.
Bad marketing part III failure of communication
Failure to publicize the great features of its cameras, such as real TTL flash support.
3. Mediocre speed. Read and write speeds of Pentax cameras are better than Fuji (a well known slug in that department) but are not as good as Canon or Nikon. No 5fps model.
Not sure about the in camera JPEG's crummy reputation. According to Phil Askey's tests and others, the difference in resolution between JPEG and raw are minimal (not visible until blown up at the pixel level). I shoot with Pentax and I do try to shoot raw as much as possible, but I won't hesitate shooting JPEG.
