Originally posted by bossa
.. Is this a possible reason that many lenses for Pentax mount are being discontinued?
For third party manufacturers, the K-mount is a slowly dying mount.
Which means, if third party needs to economise, and need to streamline their production to make it profitable, non-selling or low-selling items go first and Pentax mount is to go first. That has just happened to Sigma 70-200, which is no longer available for the K-mount. One more lens no longer available.
We want to believe that they don't make lenses for Pentax because "Pentax is up to something" but that theory does not hold water. The lenses are being dropped off during the last few years more than ever before, because to third party lens manufacturers, Pentax mount was lowest selling, and they predict will be the lowest selling in foreseeable future. Simply not worth bothering about.
If Ricoh does something positive and bold for the K-mount, some lenses will return back. But if Ricoh does not invest in Pentax as expected (or as we hoped for), why we should expect others to cling to Pentax?
If you had a lens company and waited to see, or understand, Ricoh's moves, you would drop the K-mount straight away, because your precious investment would only sit idle.