Why do I have two parallel gas pipes?
The concern that I know of is about the size of the pipe and all appliances that can be running at the other end.  So if they ran out of a larger dimension pipe (or just had a lot of the smaller dimension) this would almost make sense.  But I'd think any normal installer would try to minimize the parts cost and split it closer to the appliances.

However, if the second appliance was added later, the existing line may have been too small, and then it would be cheaper to run a separate small line rather than replace the existing one with a new large line.