[thaumasiotes]

Utterances in any natural language are always ambiguous, often hopelessly so. It works out because the speaker and listener are cooperating towards a shared goal; the removal of this assumption of cooperation is why contracts and legal codes get longer and longer over time as they try to deal with the fact that they can't actually specify anything the way they'd like to.

The computer isn't like another person, and we'd really prefer to have it do what we say rather than guess what we want and act accordingly. Indeed, we are not yet able to have a computer guess what we want to any respectable accuracy.

(Think of it this way. In some languages you can provide compiler hints that say, for example, "this variable will usually be an integer, so please optimize for that". A natural language consists basically 100% of compiler hints and 0% of instructions.)

[joe_the_user]

The computer isn't like another person, and we'd really prefer to have it do what we say rather than guess what we want and act accordingly.

From the point of a view of a programmer, yes.

But isn't this kind of the division point between a "good user interface" and a programming language.

Lots of user level system are intended so the computer guesses what you want and does that.