To answer the surface question, "Is it too easy to post your code for review?", the answer is an emphatic No. It certainly is not too easy to post code for review. I don't think it could be too easy. In fact, it should be as easy as possible to come to our community and ask a question in my opinion. I'm not saying there shouldn't be barriers to entry, but those exist and we do well at closing off topic questions quickly. We do a great job of policing our site and should be proud of the quality we maintain.
Truth be told, we already have a reasonably high barrier to entry. It's difficult to ask a good question on Code Review. A good question often contains a lot of plain English context in addition to the work involved in formatting both the text and code in a way that facilitates a review.
Let's dig a little deeper into what I think is the real core of your question though. You're concerned about zombies (unanswered questions), right? You're worried about questions going unanswered? Let's put that into perspective, shall we? As I write this, these are the current unanswered stats for 3 of stack Exchange's programming sites.
- Code Review - 1276 unanswered; 22,852 total; 5.58% unanswered
- Programmers - 1200 unanswered; 35,659 total; 3.37% unanswered
- Stack Overflow - 121,178 unanswered; 9,191,156; 1.32% unanswered
So, out of the three, we perform a bit worse, but over all, not so bad. Particularly when you consider that it takes quite a bit more time and effort to answer a question on CR than on either of the other sites. Should we be concerned? Yes, but does that mean we need less questions, or more answers? I don't think anyway would say that it's a sign of a healthy site to have less questions.
So, I'll repeat the sentiment in one of my earlier comments.
I think part of the issue is that there aren't enough reviewers in
general and certainly, some languages suffer from this more than
others. So, rather than "Do we need to make it harder to ask?", we
need to ask ourselves "What can we do to attract more reviewers?".
We won't attract more answers by sending questions away and alienating users trying to get help with their code. There's a natural progression to the way people get introduced to SE sites.
- Find site.
- Read many Q & A's without an account.
- Create an account and ask a question.
- Read many more Q & A's, only now I have an account, so I vote.
- Stumble across an interesting question that I feel I can answer.
- All those upvotes are a rush. I'm going to answer more questions.
So, in my humble opinion, we should be trying to find ways to encourage people to go beyond browsing and asking questions to answering them. I perceive that this is where the progression stops for many of our users. We don't need to make it harder to ask a question, we need to make it easier to post an answer.
In an ironic twist of fate, perhaps that means more downvotes /or edits on bad, but on topic, questions.