The Internet is drowning in bots, everyone who hosts a site or service is paying the price. At least we have companies like this to make the problem worse.
You have to be a bit more restrictive today yes, but if you weren't already overrun with bots and hacking attempts while hosting a public service many years ago, you probably weren't hosting a even medium-popular website in the first place. Same thing goes today. Slap a rate limit on it and be done with it.