the fact that most of the time there is about a 0% chance the hiring manager has read the code to mongrel
Just wait a minute here! Isn't this weird? It's like hiring designers and refusing to look at their portfolios.
The interview process puts people through all these weird contortions so we can (among other things) get some indirect indications of how they code. Why not just read their code? We want to know if they can collaborate on a project, why not look at the result of projects they collaborated on?
I think in the corporate world at least, programming has become a commodity.