As someone who has a tendency to read negativity into neutral comments on the internet, allow me to point out that there's nothing in the GPs comment that suggest that it is disparaging. It is actually extremely matter of fact, and even helpful (even though it contradicted part of your original statement). Sure, the quotation could be read as snarky, but that's only because there are a lot of shitty, snarky people on the internet that use neutral language to be jerks. It kind of spoils the well for everyone when neutral direct language is transformed into mean, hateful sentiment, but this comment gives absolutely no outward indication that it is of that sort. Whether or not it was meant to be snarky, as people who communicate often on the internet, we would all be happier if we had the ability to take such comments at face value.
And to be clear, if I had made your original comment earnestly, and received the GPs reply, I am not at all certain that I wouldn't take it just the way you did. I'm just pointing out that it needn't be taken that way.