It is nothing special to talk the talk. Indeed, it would be considered a negative unless you also walk the walk. *We usually use "he's all talk" to describe someone who talks themselves up (physically, morally, whatever) and the challenge is "yeah, but can you walk (the walk)". I assume "he walks the talk" is merely a contraction of the original quote and hence easier to use. To ttt and wtw is to back up ones claims with actions. The quote is usually applied only when the claims are outlandish, and hence the wtw is usually in the negative.