There is no reason why you can't load the baggage and passengers at the same time. They're not conflicting so not sure the logic is correct here.
Fact that bus and the loaders are on the same side is precisely the reason why you can't load the baggage and passengers at the same time.
Time to arrive for the bus is not always the same so, even if you don't see a conflict now, it doesn't mean there might not be one in a different situation, that's why in this case ( cargo doors on the left ), passengers and cargo is not done at the same time, to be sure this will never happen.
As explained so many times in the past, GSX vehicles are not completely aware of each other at any time, because this would not just put lots of strain over Simconnect and the sim ( every vehicle should monitor the current position of all the others, continuously ), but doing this would introduce a whole new class of issues, like deadlocks of vehicles yelding to each other on the apron, which are very difficult to solve and already plague the default AI system, so we prefer to just skip the whole issue altogether, meaning some service cannot be performed at the same time, for example in this specific case when the loaders are on the same side as the passengers.
