Re: What's the point of CSP anyway?
"It's more like you installed a pipe from a service that promised to deliver manure, then got upset when your careful shoveling did not reveal sufficient horses mixed in, and decided to complain about the smell."
No, you've missed a rather important part, albeit one I didn't make clear in the analogy - I did not sign up to a service that promised to deliver manure, I signed up for a horse. The website insists on trying to dump manure into my house at the same time, and Adblock, Noscript and similar are attempts to block the manure while still being able to ride the horse. Since there is no contract requiring me to accept the manure and no legitimate reason for it to actually be there, they're left with complaining that blocking it degrades their ability to check the manure for purity. Which completely misses the point that I don't care how pure the manure their dumping in my house is, I don't want any of it.
In fact this is a particular good analogy since horses inevitably come with their own supply of manure, and people are generally perfectly willing to accept that small amount that is necessary for it to function normally. What we object to is the attempt to stick a sewage pipe into our homes at the same time with no justification other than that since we're OK with a small amount of unavoidable shit, we must also be fine accepting whatever amount their able to shovel in after it.