In reality you still have many sites, that infringe on copyright and display ads by Google. And some of them have done so for a long time. Having a policy is one thing, implementing it another.
You see comments like "Y does something bad too" on a story about X very frequently. May not be meant as a justification, but I think they are often distracting from the actual topic. If you went through the Terms of Service of similar services, you can probably find countless upsetting examples. So what is the conclusion? Let's just take it as it is, because everyone is doing it or abandon all services instead?