Is it acceptable to not parse unittest blocks when unittests are disabled ?

[ixid via Digitalmars-d]

On Thursday, 30 March 2017 at 06:53:47 UTC, XavierAP wrote:
> On Wednesday, 29 March 2017 at 11:16:28 UTC, deadalnix wrote:
>>
>> Is that an acceptable tradeof ?
>
> I would consider this harmful... The spec already states this 
> about unit tests, so I'd guess the decision was taken in the 
> past conscientiously.
>
> If you're worried about compilation time, you can always define 
> your unit tests in separate files that are included for 
> compilation only when needed.

Why is it harmful (actually asking, not telling you you're 
wrong)? I thought we were going to use a pay for what you use 
philosophy, if a unit test is not run then why is it paid for?