The reason why this is not done is, that you might want to use virtualbox-ose to manage containers and disk images only, without the possibility to run them.
Then, not having to install virtualbox-ose-source (plus the DKMS "overhead") is not required.
Ubuntu tends to install recommened packages now (depending on the tool you're using).
I'm leaving this bug open for discussion, especially since such a dependency appears to make more sense for virtualbox-ose-guest-utils after all, which could depend on virtualbox-ose-guest-source.
The reason why this is not done is, that you might want to use virtualbox-ose to manage containers and disk images only, without the possibility to run them. ose-source (plus the DKMS "overhead") is not required.
Then, not having to install virtualbox-
Ubuntu tends to install recommened packages now (depending on the tool you're using).
I'm leaving this bug open for discussion, especially since such a dependency appears to make more sense for virtualbox- ose-guest- utils after all, which could depend on virtualbox- ose-guest- source.