I understand this story, and I have heard it many, many times - but I do not understand how something that is possible for thousands of hobbyists writing text e

I understand this story, and I have heard it many, many times - but I do not understand how something that is possible for thousands of hobbyists writing text editors on their weekends is not possible for professionals! "You can't buy Linux-compatible software because it is too difficult to write. Instead, get it for free."