It's easier to build more complex things on top of simpler primitives than vice versa. So a simpler base layer (say TCP/IP for the internet) opens the doors to more complex things on top (say http or JavaScript).
You don't want a Solidity bug (and there are many) to mess with the supply or ownership of Bitcoin. The limited/simple scripting language is there for a reason. It's easy to add complexity and more functionality at Bitcoin base layer: the decision to not do it is the hard (but in my view the right) choice.
It's easier to build more complex things on top of simpler primitives than vice versa. So a simpler base layer (say TCP/IP for the internet) opens the doors to more complex things on top (say http or JavaScript).
You don't want a Solidity bug (and there are many) to mess with the supply or ownership of Bitcoin. The limited/simple scripting language is there for a reason. It's easy to add complexity and more functionality at Bitcoin base layer: the decision to not do it is the hard (but in my view the right) choice.