Sorry tater for not getting back earlier, but I was on vacation at "Hotel Mama"
Anyway to have "user-made maps" for Il-2 (in the sense you mean) it would have had to have been a design decision well before the project "Il-2 Sturmovik 1.0" was ever made public. Oleg said that they never planned to have more than "Il-2 Sturmovik 1.0" (plus bugfixing patches) and were simply surprised by their own success. It's not really fair to blame them for "bad planning" when their own plans were thrown out of the window after the initial release. What
could have been done was to structure the 3rd Party process a lot better (both plane and map wise) but I'm not sure if I'm reading too many of my own wishes into that. I still don't know how several people actually got the tool so it might have been a case of "I know someone who knows the designer's favorite hairdresser's second-grade cousin"
EDIT: Since you posted while I was typing. Don't blame Oleg for the content choices of RRG. The late addons were drawn up by Saqson and luthier.