I think you really nailed it with this one. I can imagine there being a normal distribution of 'separateness' of software and the rare top tail-end of the dist

I think you really nailed it with this one. I can imagine there being a normal distribution of 'separateness' of software and the rare top tail-end of the distribution gets it perfectly right, most are in the middle somewhere between 'service oriented architecture' and 'ball of mud' and some are just at plain ball of mud.