That is the very nature of a forum such as FR - very few people post their identifying information - and are still pretty critical of named people in news stories.
There’s multiple FReepers that have identified as MDs, etc. What it really comes down to is that some FReepers don’t like what gas_dr (and other MDs) have to say as he says it directly and what he says goes against what they believe.
To which I say - deal with it.
What a stupid response. You can be anything you want to be on the internet. When someone here gives advice on fixing your computer there is really no need to show ones credentials. Buyer beware. When someone here is giving medical advice, you know the kind of things that impacts the health of others, he should be required by law to provide his credentials or keep his pie hole shut on such matters.