Towing requires torque, the more the merrier. Turbochargers depending on the design either produces lots of torque or lots of horsepower. But I would agree with the individual's assessment of the turbo is why you have such a low tow rating. The other reason is you are driving with a CVT transmission vs AT or MT, so there are also possible limitations there as well. Plus you have a smaller engine being a 2.0L vs the Outback which has either the 2.5L or 3.0L engine.