[koolmoe]

Sorry but that's like selling someone a car and saying "Oh you want the chassis to be made of metal instead of wood? Well you can change that can't you."

Except pg isn't selling anything, he's just letting you see and use what's ostensibly made his life easier.

I'd modify your simile to something more accurate, but modifying similes is a black hole.

[axod]

OK, he's giving us a car with a wooden chassis. Might be a great car, fun to drive. But it will probably need the chassis replacing unless you want to crash.

[koolmoe]

It's more like he gave you a scalpel, a tool that's great - even indispensible - for a specific set of cutting tasks, but that might leave you disappointed if you chose to use it for cutting down a tree.

Except that scalpels aren't really all that extensible.

See, I told you it was a black hole...