Moroccans are largely Maliki. ISIS is Hanbali. More specifically, Wahabi. Wahabi sharia is this: From a Wahabi standpoint, Maliki are takfiri, or apostates, which is hella worse than kafiri, or unbelievers. Know all those poor townfolk that ISIS slaughters en masse without getting confession videos out of 'em first? The ones where all they're good for is bodycount? Those are takfiri. Belgium was attacked by ISIS because there are a lot of kids in ISIS from Belgium.
Maliki school's sources for Sharia are hierarchically prioritized as follows: Quran and then trustworthy Hadiths (sayings, customs and actions of Muhammad); if these sources were ambiguous on an issue, then `Amal (customs and practices of the people of Medina), followed by consensus of the Sahabah (the companions of Muhammad), then individual's opinion from the Sahabah, Qiyas (analogy), Istislah (interest and welfare of Islam and Muslims), and finally Urf (custom of people throughout the Muslim world if it did not contradict the hierarchically higher sources of Sharia).
Quran and then trustworthy Hadiths (sayings, customs and actions of Muhammad)
Ahh.... But as your link suggests: Morocco actually hates ISIS... The article - and this attack - could easily indicate ISIS does not hate Morocco. Belgium was attacked - but so was Brussels. Brussels is the HQ for the EU. Belgium does not own the image of the targets in the attack, it merely houses them. I am curious whether the attack is simply a direct target of Belgium, which I may add (through the testimony of natives, and those who lived there for a period of time) that Belgium is already a particularly divided country - or a strategic attack in connection with this recent ousting of Morocco from agricultural commerce with the EU. What does ISIS have to gain by attacking Brussels in addition to promoting terror within the region?
No, my arguments and my links indicate that ISIS hates Moroccan Muslims, at least, more than they hate Europeans. Europeans are heathen. Moroccans are apostates. What does ISIS have to gain in addition to promoting terror anywhere? Their goal is to draw The Far Enemy into a world-ending cataclysmic last battle in mesopotamia. Arcane disagreements over things like grain shipments are wholly out of their wheelhouse.