Not only is it wrong, it's backwards: the US has some of the only refineries capable of processing heavier crudes, and so other countries depend on us to refine it, especially Canada. US is a net energy exporter, and ship out a lot of light crudes.
Edit: Maybe GP comment means we don't have as much capacity to refine light sweet crude? That's probably true, but wouldn't be financially advantageous to do so.
Even if the US lacked refinement capacity (which is obviously not true), significant capital investment as implied by the OP is not something the U.S. lacks.
This for sure. Its far easier to rework a refinery designed for heavy, sour oil and make it ready to process light & sweet. And WTI is very light & sweet. More and more refineries in the US have moved to processing more and more light/sweet crude oil as the level of imports lessened.
Edit: Maybe GP comment means we don't have as much capacity to refine light sweet crude? That's probably true, but wouldn't be financially advantageous to do so.
https://www.eia.gov/todayinenergy/detail.php?id=54199