Because its easier to generate code for a stackbased language since you dont have to name the intermediary values? Just a guess because I didn't read the article yet.
It does get in the way if you eant to run two instances of a game (one controlled by keyboard the second controlled by gamepad so that you can play with a friend) I've used sandboxie to get around this.
Overhead of unit testing is why I'm not a fan of it for personal projects. Testing even the simplest 400 lines of code needed more than 1000 lines of testcode and I'm doing as little as possible.
My new gas car cost me 8000€ and gets 40mpg in practice (manufacturer says 50mpg but its obviously wrong) and I just happenbto be commuting roughly 40 miles (roundtrip) per day. That's about 800 miles a month just for the commute. At $5 per gallon that's $100 per month. Would you really say I'm rich?
And C# is a Java clone which is a C++ clone which is a C clone. Who cares if languages take other languages as inspiration? Would you prefer a Disney-like situation where innovation is stifled because that is no longer possible?