(Back) When they offered the unlimited plan, it was inconceivable that people would be able to use more than about 4-5GB with serious OCD usage.
If that is his business, and he is using that much data... by what rights should everybody else be paying more to support him?! You should be able to get a 10GB contract rate with the carriers. In two years, they should be able to support a 40-50GB contract rate at a reasonable price. But, expecting "unlimited" to cover the 1st percentile and the 99th percentile equally and at the same rates is juvenile.
The only thing that's juvenile is trying to suggest you or anyone else can pass judgement on what is acceptable for an UNLIMITED data plan, just because you "don't see the need" for a particular level of usage.
Regardless, throttling at 2 GB is beyond inappropriate, and does even make sense given their current 10dollar-per-gigabyte plans.