Barriers to entry. Different services will require different levels of security. This might be enough for a simple poll app.
If you're a script kiddy who knows how Selenium works, you can crack this.
What this does for resource-poor attackers is implement some wasteful form of rate-limiting. But then, why not just use actual rate-limiting?
Barriers to entry. Different services will require different levels of security. This might be enough for a simple poll app.