Grotto, there isn't room here for flexible thinking or alternative points of view, because that will lead children to fail reading according to those who believe it. They are passionate about kids' reading, which is great. I've read a wide range of literature on the topic, some agreeing with Mumsnet's seeming consensus and some deviating from pure phonics.
From what I've read, pure phonics actually leads to higher test scores in the early part of elementary. This is because a child is used to being drilled in a certain way and knows how to respond (see: phonics check). In upper elementary, the children learning pure phonics lose their advantage as the phonics moves from learning to read to reading to learn.
It's fascinating actually. Phonics should be a major part of any literacy program, and no one disagrees with that. Fluency however can be overlooked by a pure phonics approach in the drive to have children sound out every word. Many children don't even initially realize that they can just say a word when they know it.
You're not alone in having another perspective. It's just not the popular one here, or the minority is very vocal.
For the vocal phonic proponents, I'm not anti-phonics in the least. I'm not advocating the dreaded "mixed methods." Letting kids absorb whole words on their own while they learn to read by telling them is not the same as teaching via a "mixed method." If a child reads "come" /k/ /o/ /m/ /e/, you can safely tell them the actual word without discussing first split digraphs and how this word is an exception to that rule.
In the past, all children learned to read simply by being read to. Reading to your children is the only parenting activity proven to improve your child's school performance, and that requires no phonics. Vocabulary, whole word learning (how else do kids recognize "Thomas the Train"), and story comprehension are all valued, non-phonics skills that can be overlooked by strict phonics programs.