To be fair, it's because G1 was Autobot heavy. One thing that really impressed me when Beast Wars came along was how the two sides suddenly became evenly matched.But yeah, it's the reason why writers often had to fill in the Decepticon ranks with generic gumbies like those purple Jets etc. - what we would now call Vehicons I suppose. You rarely saw "Vehibots."
P.S.: It'll also be interesting to see how TakaraTOMY markets the Siege Micromasters, because in Japan almost every Micromaster was an Autobot, and that includes the Air Strike Patrol. Off memory I can only think of 5 Japanese Micromasters who were Decepticons - and yes, Barricade was one of them!