Then abort if it's not available? A lot of software (most?) doesn't work with an empty /dev. At least null is othen required, so why not throw urandom in there as well?
The source explains why the developers does not see aborting as acceptable: It opens a huge security hole on systems where core files are insufficiently secured. On systems that are properly secured, it's a single define to cause it to fail hard when it can't use either /dev/urandom or sysctl().
