I don't think that complaining about things necessitates believing that you're entitled to them. I agree that complaining about things you received for free is in rather poor taste, but I don't think that it's morally wrong in the way that you seem to think it is. If an article you read for free had a pop-up ad on it, you have not been wronged in any way and do not have grounds to sue them, but you should be permitted to voice your complaint, so long as it's of the form "I don't like this" and not "look what they subjected me to, those monsters".
Just because you expect someone to owe something to you, doesn't mean they think they owe you that thing.
If someone gives away something free, they can and sometimes do wash their hands of it. That doesn't prevent you from expressing your opinion on what you think they should change about the work, but they're not under any obligation to do anything about it.
Someone made a thing available. You can take it as it is, you can make noise about what you don't like, you can make it better, or you can ignore it and move on.
If someone is providing a mix of useful and garbage information, well, take your pick from the above.