I've been digging since long before this thread, but now I've found at least a partial answer...

Scribus coders refuse to add the feature to because Adobe wrote their EULA for Reader in such a fashion that makes them think reverse engineering the feature would bring Adobe down on them.

It's actually pretty damn dumb now looking at it... because when you read it the way they just did, it also means anybody that's ever used both Adobe Reader (since 7.0.7) and Okular, CutePDF, PDFCreator, any other software that allows the user to save data at their end, not even distribute a pdf with savable forms... Is in violation.

Infact reading it the way Scribus read it... OOo's ability to create pdfs with any fillable forums is a violation...

Adobe's been ****ing me off for years now... I don't think this is how they meant the EULA to be read, especially since it also means had scribus added the feature, someone created a form that was savable, and you downloaded it, and used it... you would be in violation, but the fact that it can be read that way is enough to add to my list of things I hate...

So I'll be finishing my document in OOo, and suggesting to everyone that downloads it to use something other than Adobe Reader to fill it out.