Yup. Been there. Done that. I recall some 20 years ago, while living in London, someone wanted me to edit a Ph.D thesis. With a month to go, I started getting anxious. With two weeks to go, I started telling her the timing was impossible. I heard nothing. Two days before the thesis was due, I got an email from her (she was on holiday in Switzerland) apologizing for the late delivery, but she was on holiday.
I ignored it A day after it was due for her to collect, she came back to me and asked me how it was going, and she could only give me another day. I told her that it takes about a month to do work like that, and that she had long skipped the agreed to dates, and that there would be no refunds.
She was angry.
That kind of thing happened over and over again, so, yes, you're right. There seems to be this belief that fixing up someone's errors is a two minute job. In reality, it's more time consuming.
So, yes, you're right. These people do think that writing is quick and easy. I think it's quick and easy when one has one's own story is one's head (and that's relative), but when one does someone else's work, one has to be inside their head, take style, purpose, mood, and a lot of other things into consideration. Not a five minute job.
That 'sample' thingie is bs. I often wonder if they simply don't collect loads of samples for some problem they put up, and then use that information for their benefit. It's absolutely obviously that if someone has been doing something for 20 or 40 years that they can do the job.