Well yes, it is true that in the real world you need more than a few ounces of tinder to make a fire...just tinder would burn about 15 seconds and make about zero heat...
But it is also true that in the real world just about anybody can gather firewood, the limitation to rangers and druids is a bit silly. I was a boy scout, I bet a lot of us were...
Its also true that having to buy and carry 10 or 20 pounds of firewood with us in our backpacks, as is true on certain other PWs, in order to have our fires in non-forested areas would be annoying
And charcoal could be craftable. But this may be opening a can of worms we dont want to open.