more than 20 times. Most human rights organizations believe that his forces has killed more than 90% of the civilians who have died in Syria. Using bombers, artillery, tanks and Scud missiles in attacking urban areas leads to many civilian casualties - collateral damage perhaps in the eyes of the government.
Assad's position is exactly the opposite of Al Nusra: "You are with me or you are with the terrorists." (Kind of reminds me of our recent republican president.)
Juan Cole has written that the jihadists are the most effective fighter man-for-man but only represent 10-20% of opposition fighters in Syria now though that percentage increases as the civil war drags on. The Free Syrian army is composed of soldiers who defected and Syrian civilians who took up arms still represent 80-90% of opposition fighters according to Cole, but the civilians, in particular, are not very effective fighters.
Assad's government is based on a minority of the population, similar in percentages to the white government of apartheid South Africa back in the day. The majority (70%) of Syria's population is Sunni just as the similar percentage of South Africa's population was Black (70% Black, 20% white, 10% Asian and mixed.
I understand that for Assad's sect to continue to rule Syria, force is his only option. He never could, and cannot now, negotiate any opening up of the political system or he is history. I also understand the fear of retribution that his and other minorities in Syria have. Decades of repressing the majority has caused a lot of ill will and this last-gasp military campaign does not seem likely to lead to a happy ending. (The current civil war is something like what many predicted would eventually happen in South Africa. Fortunately, the minority government there was replaced without a civil war and subsequent retribution - thank you, Mr. Mandela and others.)
As you said, "No matter who wins, the people of Syria lose." I agree. If Assad wins, he has to rule by force as he (and his father before him) always has or he is gone. If the opposition wins, there jihadists are not going to go away quietly and the minorities in Syria will be endangered.