People are paid to work because their labor is valuable. That is in no way mutually exclusive with how interesting and meaningful the job is. Jobs at the intersection of employer value and employee interest are obviously the most desirable. I'd imagine every laborer attempts to maximize these two qualities of their day job.
However, some roles lend themselves more easily to find meaning in them, think e.g. roles with patient contact in health care. Or the gaming/entertainment industry.
As a consequence, the competition on the labor side is much fiercer, and as a consequence of that, pay is lower and the chance for exploitation is higher.
So the GP basically has stated the contraposition of this effect: you get paid more if you do (what most perceive as) less meaningful work.
Well, again - there are these golden jobs that offer both. As an example, if you're good enough as a rendering programmer with video games experience, you can command almost any kind of salary, work wherever you want, and change jobs at a whim - because any games company will pay you your weight in gold to employ you. And (while not a given) the opportunity to work on something meaningful/interesting there is very high.
This quote probably has less meaning now than it did, but I think it still holds. Part of this though is finding joy in doing things that you don't naturally enjoy. There are miserable or lazy people that will not enjoy anything other than self pleasure.
