Here's my guess - not going to say it's the case - but I have strong suspicions....

I bet that the underlying code used to build up BIAB and PTPA and RealBand simply doesn't allow for the 'modern' button renderings and so forth. I'm guessing it's also the reason why the VST/VSTi clock timing issues and likely the ASIO bugginess.

I don't know what they are using, but it's entirely possible it's something compiled from a language from Borland from the 1990's with workarounds and so forth to allow it to function reasonably well in modern OS.

At my place of employment, we use a CAD software that is highly specialized for working with 3D files of scans of the ear canals of individuals. Every now and then, we get an accidental 'look under the hood' with certain bugs that pop up. Sometimes the look includes a section of uncompiled code and our IT guy has said that some of the code looks like Pascal from 10+ years ago.

With all that said, it's not the worst UI I've seen for a music product. That honor, in my book, belongs to this product I've just discovered over at KVR forums called ChordWare. Have a look yourself:
[image=http://www.chordwarepa.com/aaa1131.JPG][/image]