Question: Wheat Protein Isolate: Too good to be true?

I've seen this product for sale on some low carb websites
(e.g.: http://tinyurl.com/yq7oa)

The claims are that it has 1.5g total carbs per cup and .5 grams of fiber,
or net ONE GRAM of carbs per cup -- and that it can be substituted full
strength for flour and/or wheat gluten in any recipe to make truly low-carb
breads, cookies, etc.

What's the catch ... other than the fact that it's $25.00 for 5 pounds? If
this product really works as advertised, why haven't we seen *truly*
low-carb bakery goods on the commercial market made with Wheat Protein
Isolate (cookies, cakes, muffins, breads, etc.). Seems to me this would be
so much of a breakthrough in low carb baking that it would be headlines. Or
is it just the extremely high cost that is prohibitive from making it a true
everyday low-carb flour substitute ?

Enquiring minds want to know ..........

--
Peter
website: http://users.thelink.net/marengo