It's also a great topic when it comes to understanding who defends the status quo and identifies with class envy policies, be it from the right or the left.
Well, sure, if people were saying things like "the current system works great", or "I hate the rich", you could do that.
To infer those things from comments like "there are some practical problems with the assumptions used by the advocates", or "the expected shift in tax burden to the middle class is being ignored or even denied", is a great way to figure out who has problems with reading comprehension.