yes they can, but then they'd open themselves up to criticism...not sure what's 'fair game' here, but seems to me like complaining/criticizing others is indirectly saying "I can do better". Prove it.

Very few games reviewers can develop games. Very few people who review music are successful musicians.

Reviewers - except when on industry-formed panels - are rarely any good at producing what they're reviewing.. that's why they're reviewers.

His wasn't a review; it was a personal dig towards specific programmer's ability. Even professional critics usually have to make a sound argument, not just point to blunders on a blog.

It was a cheap shot and an unfair dig, but ultimately I still believe you don't necessarily need to be skilled in something to be able to criticize its proponents whether you're tactful or not. In as much as it was a criticism, it was a review of sorts.

Democracy relies on this concept of making crude judgements. The "Bush sucks" and "Liberals are socialists" nonsense is crass and often wrong, but people do think that way when voting. If we had to understand politics, economics, and government to a truly informed level, turnout would be in the single digit percentages ;-)

Thankfully, he got voted down to oblivion - so it seems like the majority believe it was a cheap shot and not worth paying attention to. Doesn't mean he was any less qualified to express the opinion though.

that's actually not even the case:

this is like a fast-food franchise owner who consistently serves poor quality food saying an expert chef (who, however, only works in a gourmet restaurant but has never run a restaurant himself) has no right to criticize their food quality because he isn't running a business.