Some might say, Pentax is slow to roll out new lenses to the market, “I think” it is more of a $$$ problem. Remember, they are not a big company [any more].
Ricoh might give Pentax XXX Yen, Pentax has to manage its resource and at the same time produce enough profit back to Ricoh. If Pentax can make more $$$, Ricoh will cut a bigger piece of cake for Pentax, etc.
And why they go for 50 and 85 mm rather than do Wide-angle lenses first. It could be their Market research which points to that direction. I am sure they have many reasons behind it. They are not randomly investing time and limit resource developing a lens no one wants.
I would say, give Pentax time. We all know they are not a big company with tons of money to throw at development teams. And I think, Pentax knows most people can’t wait has already jump the ship. So they are taking their time too