"Muslims plundered raped conquested and enslaved in Europe for 400 YEARS before the Crusades happened." Yeah, and the Pope did absolute bumpkiss about it. They didn't care! Between Tours and the Battle of Manzikert, there was NO effort whatsoever to focus Christian forces on the Islamic world.
It was a completely political calculation that came when Alexios Komnenos asked for military assistance, and the Pope wanted to do it in such a way that he could undermine the Eastern Orthodox Church and bolster the Roman Catholic authority. Nothing. To. Do. With. Islam. At all. It was JUST an opportunity, and Deus Vult was just how they were going to sell it.
If you want to talk about Christians trying to turn back the Muslim invasions religiously, you're really talking about Peter the Hermit - who went completely rouge from the Papacy AND the Orthodox church to raise a mob of peasant-soldiers without organization from any nobelmen. It was a mess. The FIRST thing they did - are you reading this? Are you paying attention? The first thing they did was attacked Jews. All across Europe. They got to the enemy lands of Anatolia having slaughtered thousands of Christians trying to keep order on their sorry asses, and not. One. Muslim. Soldier. Not one. THAT was your Deus Vult army. Not the one in the OP picture - that was retinue for a nobleman who had been hired to protect the earliest bankers, I'm not even kidding - that was a f**king bank merc. The Deus Vult guys were disorganized, messy, got cut down in droves, and Peter the Hermit himself died in disgrace.
So don't tell me I've read history wrong - you're trying to reignite a holy war that will fail in disgrace just like the last eleven did because you have learned NOTHING from the past.