What IS true is that there is no interest from existing developers to change the internal file structure used by Calibre. There are plenty of good reasons why that is the case with one of them being the huge effort that it is thought would be involved. It is not that anyone thinks it would be a bad idea if it could be implemented - just that there are major practical obstacles to getting there.
The biggest obstacle is the "No way" attitude everytime someone dare mention this... There is a topic that actually say "don't speak about it".
It's a shame to bury the problem, go for the "deal with it" attitude, instead of trying to fix things.