The explanation of Kopits graph is right on the slide, he is pointing to "conventional" oil, not tar sands mining or LTO fracking or natural gas liquids condensing. Conventional oil is the stuff the industry is built around with the other stuff overlooked or passed over or flared as waste - until now when all of a sudden it has been Discovered! LOL
Notice that on Matt's chart the volume is 73mmb/d, he is only counting conventional crude oil except for the US LTO, which he calls out.
The point isn't that you can't make stuff with those "liquids" - of course you can. The point is that pretty well as expected, the resource formerly known as crude oil peaked or at least plateaued right on schedule. Because of that the market now is limited by supply where in the past it was limited by demand.
Early on this board the question was "Yeahbut, what happens when demand outstrips supply?"* We now know what happens:
first) the price rises because try as they might no one can open the valve any wider,
second) demand begins to fall
- this is where the market shifts from demand constrained to supply constrained
third) exploration budgets rise
fourth) upon finding no new conventional oil we start burning the less desirable stuff like tar sands and the light oil/condensate/NGPL we had saved for making other stuff, IOW we start burning the furniture.
To clarify (or maybe confuse further) here is a picture of what the boom is all about.

Condensate and the light oil are selling as a substantial discount because they aren't as useful to the refiners as their equipment is currently set up.
The same article in the WSJ where I got that chart has the refiners whining because the drillers are mixing in so much cheap condensate with crude to get a better price.
My question is, why don't the US refiners simply switch over their equipment to refine the lighter oil and take advantage of the lower price instead of sitting on their hands waiting for the drillers to build heater/crackers to export it?
I'd answer by saying if the fracking boom is to be a sea change rather than a bubble, they would. Just like the drillers in ND would sign up to a pipeline to save transport costs in the long run - if they thought there was going to be a long run.
*I just searched and found 68 mentions of "demand outstrips supply" on PO.com mostly back before '07 when it did. LOL
The legitimate object of government, is to do for a community of people, whatever they need to have done, but can not do, at all, or can not, so well do, for themselves -- in their separate, and individual capacities.
-- Abraham Lincoln, Fragment on Government (July 1, 1854)