I would say blw does become something of a religion with some people, actually
Yes. And when so things given a title/status like BLW has, people become so adamant to only use that way
It's far better to be flexible I think and not limit yourself to what one "expert" or book or group of people at toddler group do
There's more people criticising BLW on this thread than there is purée 
The BLW book is a good read regardless of which method you use to wean your child on to solids. The book talks about how and why purée is around and why it isn't required beyond 6 months old.
I'm a cynic and think baby food companies have packaged a normal baby jar of food in to a "finest, better quality" pouch. It's just the same food as jars and millions of people have brought in to the fact that the pouch is somehow better than a jar.
Baby food in a jar/pouch is basically heated at such a high temperature that any nutrients and goodness is lost in the making process.
I wouldn't eat anything with a sell by date of 3 years in advance, would you?