your suggesting this whole thing about the crusades being for 'trade routes' yet as I search christian sources, non-christian sources, historical sources, nowhere do they say yes, the crusades were fought for trade routes.
And you are telling us that people have told you this, or are telling you this, wouldn't it be a good idea to do your own research and then back your assertion by saying, here, see they did do it for trade routes. If there are alternative explanations of the crusades as 'trade route hunts' then they must not have much credence with the historical community because I cannot find it. And what the crusaders did also does not follow with actions for the purpose of establishing trade routes.
were they planning to just kill the people in the Middle East and trade amongst themselves? Even if someone knows nothing about the crusades, just logically, the actions of the crusaders do not match that of an expedition that was going out to find trading partners and routes to people they could trade with.