Why Benelli TNT 300 is made so heavy? Why are they not using lighter parts like other manufacturers?

The main reason behind TNT's weight is its engine design. Massive crank cases have been used to make it appealing which has added to the overall weight. When it comes to weight reduction then companies use carbon fibre body parts instead of metal ones. Along with that, the engine, power train weight and design of the crank case plays a major role. Even a Trellis frame is known to help in weight reduction of the bike. But a trellis frame cannot withstand pulsating impact that occurs when the bike encounters an obstacle. But despite the heavy weight, TNT 300 is a  much sought after bike.