I don't know the Quran as well as you seem to do, so I accept what you says it says (I'd like the reference though, because I think it very interesting).
However, what you've found is a fundamental human issue. Most people don't want to research, so they'll accept the word of anyone who seems to know more. That can mean muftis or even mere imams in islam, mediatic figures in the west, etc.
That's actually the root of religions' power. No one needs to think for themselves when you have someone telling you what's right and what's wrong.
However, in a form, that's just human laziness. And human laziness is our best asset. It's too much work to be an extremist, it's too much work to make war, and most technological progress are just ways to work less.
here is a fact if those people who claim to be muslims started to think and do research on their own and if they learn it properly , ISIS and all this Radical Islam will disappear.
Aside from the fact that having all terrorists doing extensive research on their own is as unlikely as what you mentioned before, all religions disappearing, there are two assumptions in your statement that I don't agree with.
First assumption is that every muslim terrorist actually cares about their professed religion more than about their extremist ideas.
Second assumption is that anyone would note the same passages of the Quran and interpret them the same as you. This is never the case with religious books.