there is no traffic at all at the gates, only some on outer areas of airport etc. I don't use any traffic add-on, just stock fs9.1 traffic...
That's the problem: you are using stock AI traffic. The airport uses airline parking codes, on the assumption most users don't use stock traffic, but some kind of add-on with AI planes with airlines codes.
If it wasn't made that way, people that DO use an AI add-on ( vast majority ), would complain their airline codes-enabled AI will park in the wrong places.
Lacking airline codes, the assignment will be done purely based on parking size vs AI wingspan, and this at KLAX will usually result in the outermost areas being filled before the main terminals and, since the number of AI is related to a fixed schedule, once all AI assigned to be there on that particular day/time are fullfiled, no more than that will be generated, so you get the impression the airport is almost empty, which is not, it's just it has filled its assigned number of AI to the peripheral parking spots first.
With an add-on AI product ( there are plenty, especially in FS9, which are even freeware ), if the parking size requirement is satisfied, the AI will park according to airline codes.
