This is a classic debate in programming, literally:

2001: "Beating the Averages" (Paul Graham) [1]

2006: "Can Your Programming Language Do This?" (Joel Spolsky) [2]

Both of these articles argue for the thesis that programmers that have been deprived of certain language features often argue that they don't need those features since they are already comfortable working around the lack of said features.

It's a fancy way of arguing: you don't know what you're missing because you've never had it. Or, don't knock it until you try it.

Consider, is your argument a) I've never used it and don't see a need for it, or b) I've used it before and didn't get any benefit?

1. https://paulgraham.com/avg.html?viewfullsite=1

2. https://www.joelonsoftware.com/2006/08/01/can-your-programmi...

I can already do functional programming like map/reduce in C# tho. Not sure what the LISP argument is. Spolsky was saying there's a perf benefit in there somewhere but I'm not seeing how unions give me that.