Technically you're right it doesn't make a huge amount of sense. But I like the system as people have already said, it promotes social interaction.
You want to live like a hermit in the mountains and have no interaction with other living beings? Fine, the game supports that but don't expect it to be easy.
Random recipes means you are forced to trade with other players in or out of your tribe. This promotes player economy in a game where there is currently no currency.
Yes, it doesn't make sense that you suddenly learn to make a Hammer after grinding stakes for a while. But you have to look at the big picture and think about WHY the system was created like that. Do you really think the Devs just threw together a random system with no reason?
I would however support some sort of reverse engineering but with a high chance of failure depending on the item..