I often take pictures of well-presented meals in restaurants. I don't have a food blog, nor am I a published food critic. I see no problem with it (I don't use flash, and my camera is set for silent operation). If you need to use a flash with a reasonable quality point and shoot, the problem isn't you, it's the restaurant not providing enough light to actually see your food.

I'll make an exception for the gimmick 'dark' restaurants with blind waiters. No photos there.