If I played DFS and I got matched up against pros I would be pretty angry. They make it seem like you are going to be matched up against people just like you, but you aren't. You're matched up against pros, because they submit thousands of lineups so they can maximize their chances of playing against as many non-pros as possible.
It's like going to your weekly office poker game and, after losing, discovering that you're actually playing against pros, not your coworkers. And to make it worse, the pros are doing this in hundreds of games all at the same time!
If you had bothered to read the article, this would have been apparent.
But you can choose to enter games that are only against your friends - I do every week. (There's nothing physically keeping a stranger from joining our game, but since they don't know the link, and we all enter as soon as one of us creates the contest and sends us all the link, it's unlikely.)
OK, I also enter other games, but in those, I typically go for the games that are small, and almost filled, so I can look at the list of other players and only enter if there are no very experienced players there.
It's like going to your weekly office poker game and, after losing, discovering that you're actually playing against pros, not your coworkers. And to make it worse, the pros are doing this in hundreds of games all at the same time!
If you had bothered to read the article, this would have been apparent.