There are several lines being pushed. My own is pretty much what you've said, but with the additional observations on other crimes that haven't been treat equivalently.
Some others are trying to argue solely along the lines you mention, which to me is futile. Apart from being arseholes for doing it in the first place, they ****ed the message for the peaceful majority, and gave Starmer a lazy excuse to smear people who are pointing at Government failings.
The ones trying to stick solely to the rioters are just narrow minded and building their own fantasy versions of other peoples views, as it suits their own prejudice and agenda. They're best just ignored.