Yes good point, PTH power devices often take up less space because they can be vertical and don't need a large heatsink plane around them as well. Bottom line is that power devices pretty much have to be a certain size for a given power and technology, you choose if that size is horizontal or vertical and in many applications vertical is using enclosure space that otherwise is not used and in fact you may even get a "free" heatsink in the metal enclosure.
In this case even a large PTH power transistor takes up almost no PCB space whereas it's SMD equivalent uses half the board.
Rob