Yes, the Continental Army was the principle military force without which the British would not have been so quickly defeated. However, you seem all too eager to criticize the role of the militia. In fact, militiamen played an important part in many American victories throughout the course of the war. In "home turf" battles, the militia held a great advantage over the British. They had lived in the area all their lives and knew the landscape perfectly.
Also, the militia served as a general emergency reserve that could temporarily fill gaps for the Continental Army. When used correctly by the Continental Army generals, the militia proved to be a threat to the British in battle. At Cowpens, General Greene did just this and won a critical American victory (he used the militia as auxiliary troops around a core of regulars, if I recall my history professor correctly).
The successes of the militia were not only in the south, though. They also played an instrumental role in the pivotal American victory over General Burgoyne in New England. The New York militia was being flooded by new enlistments and the size of the force grew substantially. When the Continental Army fought the British to a standstill at the Battle of Saratoga, the militia then arrived at the battle, leaving Burgoyne with no choice but to surrender, due to the sheer size of the combined force. The outcome of Saratoga convinced the French to enter the war on the side of the Americans, a decisive factor in the outcome of the war.
But other than that, well, the militia was of little relevance. < /sarcasm >