I read through an extensive thread on reddit (the great) about the end of drupal as a content management system. There was the usual comparison with WordPress, how WordPress offers ease of use and speed of setup at the expense of flexibility and depth. An argument was made, which I agree with, that Drupal takes longer to understand and learn, but pays more dividends when you invest in doing so.
There was also a point made about the income of the respective developers for each platform. The argument is that Drupal is better suited to bigger, complicated jobs, and so average contracts were in the multiple 10,000s (tens of thousands), whereas the average WordPress build was much lower in value. Of course, that is not to say you can earn just as much in WordPress (or just as little in Drupal).
There was an interesting point made further down the thread that caught my interest - and I will have to investigate further on this - that as Drupal specialises more and more, third party module developers will move away to other platforms. As someone who primarily builds websites out of custom modules (with very little of my own module development) this concerns me.
The thread is about two years old, and a lot has changed since then; Drupal 8 is on the horizon and looks set to change things again, but that its for the better seems undeniable now. My reading and understanding the field is still at an early stage, but I'm still happy about my choice to focus on Drupal.