Many sewing bloggers create free sewing tutorials and patterns for two reasons. The first is to generate traffic and interest for their blog, and the second is to build trust with their readers about their ability to create good patterns (and thus may purchase patterns).
Should I make my own free pattern?
What’s the worst that could happen? If you have made something through your own creativity then share it! It’s great practice to see if you enjoy pattern making, and the Internet can learn from your experience!