Mainframe programming for mere mortals

Or, why won't IBM let programmers help them?

IBM is in a comfortable niche w/r/t their high end hardware. For "real developers", there is zPDT. It ain't free. In fact, it is well beyond what most FOSS volunteers can afford. So we have free (as in beer) ways of emulating a mainframe, like Hercules. The guys who shouldered the monmuental task of emnuating the mainframe with open-source did an amazing thing. And there are some things Hercules cannot do. So there is a place for zPDT. Maybe IBM is just trying to keep certain business partners comfortable. I hear that many developers are not. (are not "comfortable", that is)