What are the worst parts of D?

[Vladimir Panteleev via Digitalmars-d]

On Wednesday, 24 September 2014 at 04:00:06 UTC, Walter Bright 
wrote:
> On 9/22/2014 10:16 AM, luminousone wrote:
>> What is needed?
>
> The people who maintain large projects need to try them out 
> with the beta compilers and file any regressions.

Question: What's the point of testing betas if the release will 
occur even with known regressions? Blocking a pull being merged 
would be much more efficient than dealing with a pull merged long 
ago that by release time is difficult to revert.