Syntax looks matplotlib-ish so we’re going back to 2003
A major reason why other plotting libraries don't take of is use of complicated APIs. But data analysis doesn't need Application Programming Interfaces, it needs User Interfaces.
of which the matplotlib is the embodiment. Terrible API with terrible terrible performance.
For architecture astronauts there's also the OOP API over which the pylab API is a wrapper.
Of course there are also a lot of all sorts of declarative APIs, which are popular with people copy-pasting code from cookbooks. These become very painful very fast if you do something that's not in the cookbook.
Matplotlib does struggle with performance in some/many cases, but it has little to do with the API.
There are indeed many ad-hoc functions, typically for commonly used cases, and they tend to cover vast majority of common use case with very simple and concise code. If you want something more custom, the underlying artist API is very flexible. But you probably know this based on the 7-8 years?
Things like subplot layouts, data point annotation and legend tweaking can be really painful. Something like a proper box/model CSS layouting would be great.
I would argue that the Matplotlib syntax is horribly broken (or rather, the Matlab syntax it historically tried to emulate, and had to stick with for better or worse..)
The problems start as soon as you try doing something more than plt.plot(), and you get your first encounter with the maddening interface differences between a single figure plot and a multi-figure plot. And then it spirals out of control from there.
There is no denying that a lot of effort was put in the library over the years, with lots of documentation and examples, but my general experience over the 15 years I've been using it is that as soon as you try doing something slightly different than the defaults, it invariably turns out to be a time-consuming, frustrating endeavour, with no guarantees that you'll get the result you want.
You're probably referring to plots with subplots. Those indeed have issues, although mostly not because of the API. This has somewhat improved with the constrained layout, within the old API. There's also now GridSpec for more control. And for EDA those don't really matter much. There are some annoying differences when calling Axis methods vs the global functions (e.g. xlim vs set_xlim).
Tweaking plots exactly as you want can get tricky, although for that the artist API can get you more or less anything you want. Care to share what's the library that gives you guaranteed results in no time and with no frustrations?
When plotting is the basis of what a library does, and there are annoying differences encountered at such a very basic usage level, then it is not completely unreasonable to express some grievance about the syntax imposed to the user.. It is a frustrating user-experience to start encountering issues at such a fundamental level.
Tweaking plots, axis and layouts is tricky. Animating a plot with a bit of control is non-trivial, although I am prepared to concede that the two are different beasts.
My most recent annoyance was for something that seemed superficially easy: duplicating a left axis to a right axis, with a different label text, keeping the "original" grid and limits. Think of degree Kelvin on the left, and the equivalent in Celsius as a right axis. After more than 30 minutes of trying, I simply gave up as it was way beyond the amount of time I could justify spending on a single plot.