I don't think this is a fair criticism of Stoicisim. It definitely doesn't say ignore the outside world or things you can't change, rather acknowledge and accept them to allow the capacity to focus on the things you can change.
>> ... [stoicism] is a response to perceiving the breakdown of a functioning world. Their prescription for dealing with such troubles is to develop profound internal strength, and in doing so the stoic attitude can dodge some societal-level failures by compartmentalizing toward a robust individualism.
Where this author speaks of "profound internal strength", stoicism talks about ataraxia and "remedies" or techniques to achieve a state of tranquility when encountering something that disturbs that state (e.g. someone calls you an idiot). Seneca's letters, for example, talk about progressing along a path and becoming more skilled, not developing "profound internal strength".
Lastly, I wanted to say "individualism" is an anachronistic modern concept the author has insinuated into the ancient world.