That was my insinuation, yes. After watching the buildings come down, I am convinced that they were brought down on purpose. What sealed the deal for me was the "pancake" motion, coupled with the puffs of smoke that descended as it collapsed. If you watch video footage of the demolition of buildings using explosives, they are identical.
Now, if the buildings were brought down on purpose, then that leaves several options open. The first being that 9/11 was an inside job conspiracy. I personally find no compelling evidence to support this. Rather, I believe that in the face of what was happening, they chose to bring the buildings down in a way that minimized structural damage to the surrounding landscape.
If the fire had continued to burn the way it was going, superheating the metal and causing a collapse, the buildings would have collapsed to one side, rather than pancaking. This would have caused much more damage than simply just pancaking the building. Also, it serves as evidence that the buildings were brought down intentionally, as they didn't collapse to one side as they should have.
As to the why, with the buildings being as tall as they were, it's possible that they thought out this exact scenario. Not terrorism, per se, but a low flying plane accidentally hitting them. Or possibly a catastrophic building fire. Or even a bomb threat.