The US-backed (financially and militarly) Syrian oppossition main task (which they are paid to do) is: pave the way for NATO intervension. The US & its allies want to restore democracy and help the installed regime there re-build Syria. But in order to re-build a country, it makes sense to destroy most of it first. And then they can move on to re-build another country.
Palestinian foreign minister filed report to ICC over torching of Duma home (Haaretz)