I think you make an interesting point about the implications of the no-VST constraint. In the earlier days of Reason (before they had VST support or even Rack Extensions) it was great because I could work on a song on any system that had just Reason installed and anyone that also had the current version could open it as is. No installing plugins and no plugin compatibility issues between users. Away from the studio for a weekend? Just install on a laptop and use the dongle, no problem!
Creatively it was very freeing. Naturally, plugin envy eventually crept in and I was glad when they did add VST support, but I miss the ease of use and portability. And you got to know the stock effects inside and out which offered some streamlining in workflow.
If you miss the portability and the need to know the built-ins in and out, you likely might enjoy SunVox, with its utter portability, surprising richness, and the need to be inventive to eke out interesting sounds from standard blocks.
Creatively it was very freeing. Naturally, plugin envy eventually crept in and I was glad when they did add VST support, but I miss the ease of use and portability. And you got to know the stock effects inside and out which offered some streamlining in workflow.