So you think that 2000 hp means nothing even if only 10 ft lbs are produced? Any of us could produce 10 ft lbs, but at what speed? You may think that diesels are all about torque because they make their power at a (relatively) low RPM but their game is still in horsepower.
Say I can produce 200 ft. lbs. on a lever. That's two hundred, roughly as much as most cars on the road. Could I push a 3500 lb sedan 80 mph down the road, or accelerate it to 60 in less than 10 seconds? Hell no. That's because at two hundred foot lbs I'd be lucky to rotate that lever a couple times a minute, that car is probably rotating 4000 times per minute.
The difference? The car can be geared MUCH, MUCH deeper to achieve the same speed and hence it puts MUCH more force to the ground. That's horsepower, not torque. Given my rough example, that car can put 200 times more force to the ground, even though we can make the same torque.
Diesels are certainly VERY useful for their jobs, I have and always have used a diesel tow rig. But to say the horsepower is useless and torque is everything is totally false.
The usefulness in engines is that they spin fast (a measure of hp), and that we can reduce that speed many times through gears to create force pushing the car/truck forward. You can manipulate torque to the ground (higher gears giving less torque at a higher speed and lower gears giving more torque at a lower speed) but horsepower stays the same regardless of gear ratio (after drivetrain losses etc.).