I'd guess it's because of the crude and reductive way you describe the service cloudflare provides. I don't know what type of programming you do, but many small services don't have the infrastructure to mitigate the kind of attacks cloudflare deals with and they wouldn't be around without services like this.
I don't like the internet becoming centralized into a few small places that mitigate DDOS attacks like this, but I like the alternative (being held ransom by anyone with access to a botnet) even less.
I'm going to take a more even handed approach than what you're suggesting. Any time you work with a service like this you risk these kinds of things - it's part of the implicit cost/benefit analysis humans do every day. I'm not ready to throw out the baby with the bathwater because of one issue. I'm not sure what alternative you're suggesting (I didn't see any suggestions, just a lot of ranting, which might also contribute to the 'revulsion') but it doesn't sound any better than what we have.