As an attempt to clarify what was the reasoning behind this decision we reached out to the project’s mailing list. Klaus Espenlaub, one of the VirtualBox developers, claimed that in 4.0.4 a field was renamed for the sake of clarity and in 3.0.2 there were “more
intrusive” changes but that the removed methods were “not really useful” and because this functionality had been made available for a 10-day period (between version 3.0.0 and 3.0.2) they found “the probability of breaking existing third party code was negligible” and thus “decided it was worth it”.