In that case then the service will just hang as it won't handle the requests caused by even a simple malfunction (not even an actual attack) like the one mentio

In that case then the service will just hang as it won't handle the requests caused by even a simple malfunction (not even an actual attack) like the one mentioned by GP. Mind you, I see your point and I generally don't like the captchas either, but it is definitely a trade-off and I won't blame webmasters that use the DDoS protection.