Your disappointment is understandable!
The NHBC should be doing much more than just stating what the NHBC does and does not do.
Especially as what you have highlight would appear to indicate a breakdown in some of their systems and procedures.
For a start I am of the opinion that the site manager should be stripped of his "quality award"
If a site manager were worthy of an NHBC the PITJ Quality Award, he would not hand over a house with such bad workmanship and hundreds of basic snags and defects.
Even if he had been on holiday, his very 'persona' would mean that his assistant and the various trades would fear reprisals on his return if the high standards he demands were not maintained during his absence.
Whilst it is possible to have a few minor defects, even in a home built by an 'award-winning' site manager, over 300 basic snags is not an indication of good quality.
Even Taylor Wimpey's own directors now acknowledge that it will take (at least) 10 days to complete [up from 8 days] all the remedial works required.
I agree that the NHBC cannot have any role (or blame) in the electrical certification as they would have no knowledge of the background or qualification of the electrician(s) or the electrical contractor. However the NHBC is incorrect as:
"Only an NICEIC Approved Contractor or Conforming Body responsible for the construction of the electrical installation is authorised to issue this NICEIC certificate."
It is therefore mandatory for the electrician carrying out the inspection to be approved by the NICEIC.
The 27 electrical faults in your home also demonstrate that new homebuyers cannot rely on certification and warranty standards as any guarantee of certainty, for either compliance of regulations or the quality of their new home.
It is hoped that the NHBC will take a far more proactive stance than their letter would appear to indicate, with regard to helping you achieve resolution of the hundreds of defects in your NHBC inspected, Buildmark warranted, PITJ Quality Award winning, Electrically certificated, Taylor Wimpey built new home.
I am sure that when BBC Watchdog feature your story, the NHBC will be mindful to ensure they have acted responsibly and properly on your behalf as a home buyer.
Quite what evidence you have as a new homebuyer, that the NHBC has indeed "raised standards" is not readily evident.