This is a good article on the problems with our limited air efforts in Syria. This sums up the problem:
“There’s a disconnect between a stated American policy that recognizes you need a credible local force on the ground and a campaign that is undermining those local forces,” said Noah Bonsey, a senior analyst at the International Crisis Group who is monitoring the war from Syria’s northern border with Turkey. If the U.S. government doesn’t speed up plans to support the Free Syrian Army, “a year from now there might not be any moderate rebels left,” he said.
I think we are probably right not to do much more in Syria from the air--although I'd make exceptions for stopping big ISIL advances like at Kobane. I know that the current administration thinks all problems are nails spotted from 20,000 feet up, but air power isn't our only tool.
We can do the things that we can do back when I figured we could oppose Assad without providing direct air support: Arm moderate rebels. Provide intelligence and training to them. Provide humanitarian aid to rebel areas whether Assad likes it or not. Support Turkish desires for a buffer zone and no-fly zone over that buffer zone.
Do these things and we support anti-Assad forces without having to use our air power as more than a secondary effort in the larger war against ISIL.
Do these things and the moderate rebels can make gains to complement our effort to recruit and train new rebels for use in the east along the border with Iraq.
And start increasing the air offensive in Iraq to at least make ISIL divert resources from Syria to Iraq to hold their gains (and subject those moving forces to our air attacks) or else risk us winning in Iraq and pivoting to Syria as the main effort sooner.
That would support the anti-ISIL forces without dramatically ramping up our air strikes in Syria.
And it avoids the problem of giving Assad a victory over the rebellion before we are ready next year and put those newly trained rebels we want to field in an impossible position of being the only force other than jihadis in the field against Assad.