You can go to so many levels with something like this!
Power is rate of work done, torque is the ammount of work done. So the logical answer is "theres a comprimise".
Torque provides basically forward motion, more of it results in higher acceleration.
The best analogy is a diesel versus petrol powered cars. Typically a diesel has high torque and lower power output, and pterol vice versa. With the diesel you get a good initial surge of acceleration, but this drops off when you hit say 4000rpm. With the petrol engined car you have less initial burst of acceleration, but its carries on pulling for longer. This is a good practical example.
Its also possible to have both. the most common method/example is a turbocharged petrol engine. They typically make very good torque spread with high peak power figures. The down side of this is tractability, and how useable it actually is. As with most principles, theres a large pay-off at a certain point.
In terms of engine development, the large part is getting the torque curve to suit the intended usage. This is the decided in having a usable engine, which results in a quick car, or an engine with impressive peak horsepower, but has such a small torque band, that its a dog to drive and ultimately slow. This is another subject really though.