I'm another of those in the minority, I bought CMAK first, then CMBB. I've never played CMBO.
The reason I bought CMAK was that my main interest in WW2 is the campaigns of the NZ Div. and CMAK allowed me to play out nearly all their battles.
I know BFC is hesitant to release the CMx1 source code, is this mainly to do with lack of documentation? There is another game out there that had the same problem, Rowan's Battle of Britain.The source code was released to a bunch of enthusiasts (called the BDG) after Rowan went bust and they continued to develop it with no documentation for 500,000 lines of code.Now the game is thriving as Battle of Britain 2.
I help out with the BDG and they've managed to work out what most of the code does. Now they are starting to add more features and use the engine for more games. If you did release the CMx1 code, there will always be a few dedicated people to see what they can make of it.