The simulation starts with each user having 14 channels open - seems like quite a strong assumption for a serious test (starting with 0 channels for each user and then randomly opening new ones would be much more interesting). After a talk by one of the lightning devs I also got the impression that they are betting that several hubs with thousands of channels would quickly emerge - due to the fee gained by running a channel. Needless to say this would undo quite a bit of the decentralized nature of bitcoin.