Because of the way Building 7 came down and under the circumstances in which it came down. I mean, why would a building that wasn't even hit by a plane and had only some scattered fires on some floors fall as perfectly as it did in the wake of two other buildings mysteriously turning to dust before our eyes that same day? It's not hard to see why people would want to know.
I still think it was an inside job, and most people I talk to suspect this as well, but aren't sure "who" "they" are, what can be done if anything, etc.
Nothing probably can be done BUT BRINGING THIS FACT TO THE SURFACE (Sheeple level) is quite important!
It wouldn't, ever. I mean...that's just ridiculous. It makes you a little stupid just to have to ask the question, like you really have to question your own sanity. But no, a few scattered fires in a building isn't going to make it collapse.