The military action that was taken against the Syrian govt is in support of the rebels, few or none of which can be differentiated from ISIS. If and when these same rebels prevail in Syria, similar to what was done in Libya, the outcome will be owned by the interventionist. If Israel supports the Syrian rebels, there is no meaningful difference between that and supporting ISIS.
If Trump fires 59 missiles on a Syrian airstrip and a much larger number of missiles on ISIS, then there is of course a meaningful difference between that and supporting ISIS.
But the media doesn't tell you about all the missiles Trump is firing on ISIS, so you don't consider it.