Not only do you still have to spend energy mining and transporting coal, but the energy spent refining the coal is immense compared to what refinable products you get out of it.
There is also market evidence where people are more willing to put their money into technological development of fracking than liquefaction.
It's best to be suspicious whenever a source suggests that coal liquefaction, and other processes like it, are that simple. A good book on the topic is Oil 101 by Morgan Downey.
