It's not a borderline case. People have trouble with the distinction between a judgement about a word overall, and a judgement about what a word will do to an HN thread. Also, people just like to gripe.
Yes, this is actually not unusual. People need food, water, shelter, and suchlike in order to survive, and so they exchange their labour for goods and services. Money is a helpful token now rather widely used in this bartering process.
I know it's quite common in the web development community to take a lot of freely provided code which took immense labour to write, and then stitch it together, in a way that requires very little skill or effort, in order to sell the result - but this isn't the norm in the world at large.