He probably is defending ISIS, as DevilsAdvocate suggested, because he very clearly has a Sunni ideology, which has wholly been infiltrated by Wahhabi and takfiri thinkers. If you're wondering what Wahhabism is, its a super conservative Sunni branch from which we have the likes of the Taliban, Al Qaeda, ISIS, Al-Nusra, and probably the majority of all their "Syrian" rebel group allies.
If we want to look at ISIS from an Islamic perspective, we can look at the history of extremism in Islam, which began at least during the reign of the 4th caliph, 30 years or so after the Prophet Mohammad had died. The first "extremist group" in Islam were called the Khawarij, and if you want to learn about them you can follow this link
https://en.wikipedia.org/wiki/Khawarij
There is also a hadith from the Prophet Mohammad which can be understood as a reference to extremism:
"There will come a time when a group of people will leave our ranks. They will recite the Quran with fervour and passion (lit. "With tongues that are moist") but its spirit will not go beyond their throats. They will leave our ranks in the manner of an arrow when it shoots from its bow."
What I believe this means is that Mohammad is suggesting that an extremist Muslim has actually left Islam (from the perspective of God) but will continue to act on what he believes is the behalf of Islam & Muslims.
The idea that is central to groups like ISIS is takfirism
https://en.wikipedia.org/wiki/Takfiri. They believe that there is Muslim and there is Non-Muslim, and those that are Non-Muslim must either be terribly subjugated, and if not, killed.
And I'd like to ask why Muwahid believes the Rashidun caliphate was a golden standard for Islam. Is it just in the name? And if there is some legitimate reason that you believe the first 3 Caliphs were in fact, great leaders, I'd like to know how you would explain Abu Bakr's act of waging war against those who wouldn't pay him allegiance... and maybe.. this:
https://en.wikipedia.org/wiki/Umar_at_Fatimah's_house ?