The bombing of ISIS and not the thug Assad’s Alawite military and paramilitaries was bound to push his opponents into alliances with ISIS. Naturally the Guardian cherry-picks and claims that the bombing of ISIS is seen as an attack on all of Islam, which is similar to the blame-the-victim horse crap that happened after 9/11, and happens every day to Israel.
Jihadists are jihadists. Factions align with other factions, fight and kill factions from their own sects as easily as they fight and kill factions from other sects.
That's the way the vast majority of Muslims really think, which is why Muslim governments have to lie their butts off about their cooperation with the US on anti-terrorist matters (intel, ops, drone targeting).