Wasn't he essentially the main villain though? He ordered Ronan around. Ronan may have been the focus but it was all on Thanos' order. That'd be like saying Talon was the main villain of Batman in The Court of Owls story arc when The Court was the villain and the one ordering Talon but Talon was the one fighting Bruce the most.
Theirs a scene where ronan betrays Thanos. Ronan becomes the main villain for the rest of the movie
I suppose, I viewed Thanos as the real main(shadow) villain of the movie.
well it's not over yet. Thanos is sure to take the reigns in the next installment or 2
Of course he will, we were talking about the Guardians movie specifically. It felt to me as if the end scenes were implying Thanos was the real villain of the movie.