The narrative coming out of Washington and the MSM is that al-Assad is a tyrant, and murderer of his own people. If that were true, then it would logically follow that he would not be supported by the Syrian population. Let look at this issue a bit closer:
"Furthermore, they completely disregard the popular support the government maintained throughout the whole conflict, which can almost completely be established by admissions in sources linked to Assad’s adversaries. A Turkish poll from late 2011 showed that only 5% of the Syrian respondents supported violent protest, while 91% opposed it,[22] and a Qatar-sponsored enquiry from around the same time found that 55% of the Syrian population wanted Assad to stay.[23] In addition, an internal NATO study in 2013 estimated that 70% supported the president in contrast to a mere 10% support for the armed opposition.[24] After constitutional amendments following a referendum, the first real democratic and competitive presidential elections in decades were held in 2014. Although Western media were quick to dismiss the credibility of the elections, the over 100 international observers present - coming from allied (e.g. Russia and Iran) as well as nonpartisan (e.g. Brazil, Venezuela and Uganda) countries around the world - issued a statement in which they declared that the elections were “free and fair” and were held “in a democratic environment, contrary to Western propaganda.”[25] Assad won the elections against his two opponents with 88,7% of the vote, with a massive participation rate of 73,4%.[26] This means that a staggering 64% of the eligible voters chose for Assad to remain in power, which is more than double of the 26% of the eligible American voters that put Donald Trump into office. As Sunnis make up 75% of the population and Alawites only 11%, this completely shatters the false representation put forward by Western media and officials of the Syrian government’s rule as a sectarian Alawite dictatorship suppressing a Sunni majority."
This is further supported in previous posts which I have linked below. I believe it is time to dispel the myth of al-Assad as a brutal dictator, and try to understand that it is Washington's post 9-11 balkanization and destabilization of mid-east countries that should be examined. I urge you to read the following article on NewsBud in order to understand the real truth of what is going on in Syria:
https://www.newsbud.com/2017/04/23/newsbud-exclusive-the-balkanization-of-syria-iraq-the-roadmap-to-us-israeli-hegemony-in-the-middle-east/Published on Apr 5, 2017
This press conference went largely ignored by the world, as you will see in one shot later in the video (10:30) the audience is bare and miserable. Most journalists refused to attended the conference and listen to the truth.
https://youtu.be/lGq6aLTOF_IHave you read the article in the Guardian stating that a recent poll (YouGov Siraj poll on Syria commissioned by The Doha Debates, funded by the Qatar Foundation) states that 55% of Syrians want al-Assad to stay, motivated by fear of a civil war.
https://www.theguardian.com/commentisfree/2012/jan/17/syrians-support-assad-western-propagandaHow about this one:
The Inconvenient Truth: Assad’s Popularity Confounds NATO Propagandists
http://21stcenturywire.com/2016/06/25/the-unconvenient-truth-assads-popularity-confounds-nato-propagandists/You ask a number of questions including "Why do so many rebels not affiliated with ISIS throw away their lives to get rid of him?" Answer, they are mercenaries recruited and paid by the Saudi's and other countries that have economic interests (gas and pipeline routes), and countries such as Israel and Turkey that covet Syrian territory and have security issues. Don't overlook the U.S. oil-and-gas industries, including pipelines (oilfield services) as well as marketing (Exxon, Halliburton, etc.).
http://www.zerohedge.com/news/2015-09-10/competing-gas-pipelines-are-fueling-syrian-war-migrant-crisis