Horst-Helmut, there will fortunately or unfortunately always be the 'need', or should I just say demand, for higher performing gear, both with cameras and lenses. No doubt, the camera companies live and thrive off this demand - after all, if every Pentaxian were content with a *ist D there'd be no camera body sales and no money for further R&D and upgrades.
So perhaps you and I aren't going to be Pentax's favourite customers, nor is Pentax seeking to address our 'needs' - they'd be looking more towards newbies and enthusiasts keen to progress up with each model and lens that is produced and fits their requirements...
This is fine - it's a good thing. It keeps Pentax going, and discerning users thinking...