A transistor is not a current amplifier but ruther a voltage amplifier. What you get at the collector is the results of current flow which is gain. Beta is an impirical number assigned to a paticular load transfer function. It means nothing unless a load current is specified. The device takes more current to so it amplify voltage. Tubes are current amplifiers it takes a presence of voltage to amplify the curent. Many non thinker will disagree with that.