Well there is always two sides to a story. For example the way Marakkars fought and defeated the colonizing efforts of Portuguese, they were nothing short of legends. Then the hindu raja allying himself with Portuguese to defeat them seems treacherous as well, to the national cause atleast.
Now you might consider both Portuguese and Muslims in Malabar as outsiders so it might not matter to you.
But the fact is Mappilas are perhaps the oldest Muslim settlers in sub-continent, even before conquest of Sindh, there were sizable Arab settlements in Malabar. There were Arab settlements even before Islam, so these guys are Malabaris as much as any other caste or ethnic group. They were traders and soldiers, and while Kunjali Marakkar might be considered a traitor in your eyes, the whole Mappila community can't be. They were the ones who manned the Zamorin ships and bled and died for their ruler for centuries.
And to their credit, Zamorins often treated them quite well, either out of natural goodness in their hearts or the fact that Arabs were their most important trading partners at that time. If I am not mistaken they even went to war with Portuguese once because of their prosecution of Muslims. Muslims bore the brunt of the Portuguese atrocities in Malabar as Portuguese were coming to India when Reconquista had just completed in Spain and Inquisition was at full swing there. In their records they were calling the Muslims of India as Moors, so in their mind it was the same 'EVIL" that they faced back in their homeland.
Anyway when the British took over they gave full property rights to the Brahmins, they became the land owners and they started evicting your caste if you did not pay them an exuberant share, and you in turn forced Mappilas who with the end of Tipu's reign, formed the bulk of agrarian class to work their a** off and still starve at end of the day. This started rebellions and then when Khilafat movement came, they got a religious fervor added to their resentment and it all ended up with 1921 riots that you were talking about. So let's blame the evil Brahmins or pitting you and Mappilas in a fight because of their greed.
While I have read extensively about nearly all(I like to think so) major dynasties and ethnic groups of sub-continent, I confess I am no expert in this field, so if you have any alternate facts I would love to hear them out.