Why is `scope` planned for deprecation?

[Walter Bright via Digitalmars-d]

On 11/17/2014 3:00 AM, "Ola Fosheim Grøstad" 
<ola.fosheim.grostad+dlang at gmail.com>" wrote:
> I am saying
> that when you have <32KiB RAM total it makes sense to save space by not storing
> the string length.

I know what you're saying.

You're saying without evidence that sentinels are faster. They are not.
You're saying without evidence that 0 terminated strings use less memory. They 
do not.

(It does not save space when "filename" and "filename.ext" cannot be overlapped.)