Opposing Functional Programming

[An] important aspect of functional programming is that functions do not change the data with which they work [...] Object-oriented imperative languages such as C, Java, or Python change their state as they run.

Neil Savage, (Using Functions for Easier Programming — https://dl.acm.org/citation.cfm?id=3193776)

Many programmers define themselves through their tools, and therefore define themselves as against certain other tools. If you are a .NET programmer, then you do not use Java. If you are a native mobile programmer, then you do not use JavaScript. If you are a React programmer, then you do not use Angular. An affiliation with one tool automatically means a disaffiliation with others.

Such partisanship is a confirming example of Sayre's law: the arguments are so fierce because the stakes are so low. For people who supposedly work in a field of rationality and science, we're really good at getting emotionally brittle when somebody wants to...