I agree. It is hacky and ugly and it obviously would be nice if the devs would simply include that one-liner in the next update. The only reason I see why it could be useful is that people have a simple way to package custom sounds with their newly released vehicles all in one place. But as you said that's just a minor difference to replacing sounds.lua... I don't really see why it would make you loose the ability to load sounds from vehicles/common though.