No one is more pissed off about these guys than the Kurds, you look at the interviews the media has with them and independent journalists and they hate ISIS with a passion one was saying "They aren't human, they're monsters" because of how they tricked this guys daughter and messed around with them when they were trying to escape ISIS controlled territory.
Kurds are the most effective fighting force right now against the ISIS. However, the NATO is against giving any sort of political or technical support to them, due to the fierce opposition from Turkey.
Yep, I know all about the history, as I said, the Kurds have a bone to pick with ISIS over the Ottomon Empire of which Turkey is essentially the remnants of, in regards to the PKK as well they have imprisoned their leader too so that's naturally got a lot of people riled.