Assad has shown that his regime is too strong with Russian support and has support in the west of the country to go. He also does show some form of government/ political stability compared to that of the FSA or ISIS. It seems to be the lesser of two evils especially with the FSA rebels losing key areas in the last few months.
This documentary is pretty good and shows life in Assad government-held Syria from Fall 2015.
http://www.pbs.org/wgbh/frontline/film/inside-assads-syria/
While it seems the Erdogan government has been flip flopping on this issue, seems the recent spike in attacks in Turkey has gotten them to see that supporting ISIS against Assad was a bad move.
the FSA have been gaining areas around Aleppo recently but full on take over is unlikely due to being outnumbered and lacking other type of forces
Assad has been losing a ton of soldiers/militias to the point that there was a scuffle between Hezbollah and Assad but the FSA doesn't have a air-force and doesn't have large numbers relative to Assad's ally Iran that just brings wave after wave of militias some of which are Afghan migrants that are fighting in order to gain a Iranian citizenship
they are in experienced but Iran can just toss more and more of them non-stop
On the issue of lesser evil, Assad the man that killed more then 200k of his people and tortured thousands to death while also using things like white sulfur on civilian areas is not lesser in any way at all
the whole notion of oh we can have him if he has his elites party and act westernized while a few km away he massacres others is a twisted sense of logic.
He literally clashed with more then 80% of his country so who the heck will he govern? There is a good reason why his army is mostly made up of foreign militias from Iran/Iraq and Afghanistan.
