The WTC7 reality-deniers see it's collapse as suspicious simply because it LOOKS suspiciously like a controlled demolition....the way it falls evenly. They then tailor their responses around this.
Fortunately we have footage which FloridaBorn posted above, of a much smaller building ACTUALLY BEING PULLED SIDEWAYS, but still falling (well, the half that falls, anyway) in exactly the same manner.

Top-Down building collapse 2 - YouTube

The footage of fire in the above post is very revealing too.