The reality is most people nowadays opt for the convenience of zooms over primes. If Pentax were to ever produce a superlative wide angle zoom like the
Nikon 14-24mm f/2.8G ED, most of us wouldn't even be discussing about a 24mm prime of f/2.8. There is the DA* 16-50mm f/2.8 SDM that covers the focal range but given that many are spooked by the SDM gremlins (whether real or not) means limited options.
If affordability was not the issue, most of those who would opt for a 24mm prime lens wouldn't really be interested in anything at f/2.8 but would steer towards a fast lens of stellar optical performance best exemplified by the
Nikon 24mm f/1.4G ED. I dare say this lens easily trumps the discontinued FA* 24mm f/2. Unfortunately even if one were to be a rich Pentaxian (a misnomer if ever I saw one
), you can't buy such a lens because Pentax doesn't make one. Simply put, Pentax has not rolled out any professional grade fast maximum aperture lenses for the longest time. Even with the increase in the user base, I have my doubts that Pentax will ever do a 24mm f/2 or faster lens. But I would be happy to be proved wrong.
With the improved AF offered by the K-5 and K-r, now would the best time for Pentax to seriously consider producing large maximum aperture lenses in the near future as the long suffering issue of FF/BF that is more noticeable with fast max aperture lenses would hopefully and likely to be addressed.