Why not const by default?

[porky11]

When declaring varialbes you normally don't declare it const, and it's normally never necessary.
When variables have to be declared mutable explicitly errors may be found more easily.
This wouldn't be as in C. Is it important, that the language is like C, even if some other design may be better?

[porky11]

const by default could also be implemented by macros, but this may be difficult, becuase it's not clear, where we have types and where not, expecially for more complicated types like (array-of 2 int) (which should not expand to (const (array-of (const 2) (const int))) if they are not defined as mutable) or most concept-macro types

[BitPuffin]

I agree on this. Sounds better to me to have explicit mutability.