So, this sort of devolves to economics, at least where I work. What I mean is, the people that pay for the code don't care and don't care to know. And this is entirely rational from their point of view. If it appears to work, it's good.
To audit the code accurately (as opposed to merely giving out aesthetic advice), in most cases would involve learning the domain, and this is what's expensive.
To the business folks, we're a black box. Stuff goes in, stuff comes out. And it costs. Paying someone else at least as much to prove that we did it according to 'best practice' (I think this is what you're suggesting?) would be anathema.
There might be a business there but it's not mass market.
It's probably also worth noting that all of the above applies to other domains too. Substitute 'code' for 'marketing' quality. In some real senses, die welt ist alles was der fall ist.