Of course they're 'at risk'. The same as you are at risk of being hit by a bus tomorrow. Risk is unavoidable.
They'll either be at risk of collateral bombing damage, or being shot/exploded/executed/whatever by a radical lunatic. There is not a 'no risk' solution for Syria and it's population.
However, we can show that we've made a damn good effort at mitigating that risk for well over a year now, employing this methodology of air strikes and to our knowledge, haven't caused a single civilian casualty as a result.
Trying to obfuscate the issue by waffling about ground troops shooting people 10 years ago is pointless and does nothing but undermine any legitimacy there is to your anti-bombing stance.
I think it's mainly because a lot of people who object don't actually give a flying **** about the Syrian people dying or not. They only really seem to care about objecting, whether it be to our government or just anyone else of a differing opinion and having a bloody good argument about it in the process.