As an Engineer (but in a scientific field) I just love Matplotlib. I moved a number of years ago from Matlab and even Excel (love how I still see papers with that mid grey background and full magenta on figures).

I'm a poor data analyst and programmer but have always managed to do what I need, mostly just time series and scatter plots. Sometimes a little more involved for my ability: such as a set of heat maps with common scaling and some tiles omitted...

I see some comments about the quality of the rendering and the look, but I think the default is really good. Nice proportionality of text, lineweight etc IMO.

Anyway I'll get to my point. I really can't get any value out of the Matplotlib official documentation. I'm not going to criticize it, just say that its not compatible with my brain. On this basis, good quality and accessible literature like this is very well received.