I understand that "why django sucks" is a better, more provocative title that will get read more than "why django isn't perfect in every way and i prefer using flask for this", so i don't fault the author for choosing that subtext.
However, the general "tradition" (yes, its a tradition now) of justifying a tech/infrastructure decision with "Ah! language/framework/db made popular by others is a horribly broken mistake! you are doing it wrong!" is 1. getting old, 2. counterproductive for engineers.
They are tools. There are different tasks with different requirements. They have different pros and cons and different learning curves. Some tools are better suited for some tasks. Some tools are even better suited for most tasks. Sometimes it even makes reasonable sense to use a product that isn't the best of the best of the best if you are really certain you don't care about the dimension in which your tool is not the most amazing.
Hammers are bad for cooking eggs. Spatulas are bad for nailing nails. I made eggs this morning. Keep an eye out for my upcoming blog post: "Why hammers suck!!"