Respect and remonstration

Gratitude and respect to the learned Languagehat, who noted and recommended this humble blog within hours of its launch:
Such extreme devotion to authentic local usage deserves our honor and respect. Greetings also to the visitors who left messages below.

To demonstrate the need for this campaigning blog, may I point towards the Guardian, a frequent offender. The newspaper's excellent style guide correctly prescribes:
all mouth and trousers
not "all mouth and no trousers", as has appeared in the paper

Yet last month, diarist Jon Henley wrote, apropos David Cameron:
Surely they're not suggesting the dear boy's all mouth and no trousers?

I naturally emailed Mr Henley to remonstrate. He replied, with as little contrition as style:
hmmm
had a bit of a debate with myself about that one.
you are of course right, tho at least three reputable sources now say that "all mouth and no trousers" is now the more commonly used, and indeed logical, variant. language must advance, say !

While I'm as supportive of an evolving, living language as the next chap, the 'no trousers' variant really cannot be described as an 'advance', but rather as a barbarism. Shame on you, Mr Henley, for such gormlessness.