When I messed around with X programming I thought the base layer was primitive, but straightforward for the most part. You had to do damn near everything my hand, but it was clean and orthogonal.
Where the nightmare started is the X toolkit. It slathered on three extra layers of complexity before providing any benefit for the programmer and was so damn confusing even when you did get it working. And what did you get out of it? Athena widgets.
GTK is a dream in comparison.
Yes, the auto-generated boilerplates was stupid (and obscured so much) but it was their way of trying to get people ahead in an "easier" way.