Please do take note that I'm not saying anything like what you claim I said. I'm asking if it's something people commonly get hit by, as I myself haven't had severe issues with it.

I'm not saying others are misinformed or cargo-culting anything, just that I'm seeing lots of people who probably never get hit by DDoS in the first place (couple of visitors per day) adding CloudFlare by default as that's what they see everyone else is doing.

Of course if you do frequently get hit by DDoS attacks, there is nothing wrong with trying to protect yourself against it...