Since oil is carried by systems that use fossil fuel to move, I would say that closing the pipeline is more symbolic than practical. An estimated 11K jobs lost in specialty fields and telling the workers to "go out and build solar panels" in a place that can't compete with foreign manufacturing was a very ignorant comment. Apparently, he doesn't know where solar panels come from.
Oil spills are bad but gasoline/semi-refined oil spills are worse because it's more flammable and by having lower viscosity, it goes deeper into soil and into ground water far more easily than crude oil. If crude gets into a waterway, some of it sinks to the bottom, releasing whatever it can, for many decades. Crude that spills on the ground can be removed if the soil allows.
We're not going to wean ourselves from oil for a long time but it's time to start. Thinking that we can do that or achieve 50% less CO2 emissions by 2035 or 2050 aren't practical goals.