Mine, I have a 3/4 ton with the 6.0 for that, but it has enough torque to toe pleasantly.
It's a tough and durable engine, just not a high horsepower beast.
The guy who used it as a business truck most likely wasn't interested in going 80mph on the interstate with a toy hauler.
For towing, it's all about low end torque. The 2uz has 315 ft*lbs, my 6.0 has something like 350. Even though it has 360hp.
So even though the GM mill has 100 more hp, it's all at high rpm and delivered torque is only a dozen more than the Toyota.
We are in the middle of a horsepower war. Notice the comments about hoping the twin turbo gets put in the 4runner. Why? The 4.0 v6 is known as a "dog".
Tacoma owners aren't pleased with their 3.5 v6 and many go back to the older 4.0 motor. Why? Low end torque, despite the horsepower disadvantage.
It may seem I'm talking in circles, but the Toyota is a very durable and strong motor for towing, but it will run out of breath...you won't be towing heavy fast....but you'll be towing heavy for 1,000,000 miles.
Does that make sense?
When it was released, interstate speeds were 64mph and we barely came out of the 55 age. To most owners it will be too gutless for the 75mph interstates, at least while towing. But it has the strength to do it, just slower.