You do realise even the founder of TDD doesn't back it anymore and code coverage is a very poor metric, your words sound like a senior developer from 2010. If he's a bad developer the best he can do is read up on SOLID principles and read a book like Clean Code with good examples of how to write code.
TDD is still a fine tool and the field hasn't moved on so much in 6 years that it's a stupid suggestion. It's a perfectly viable tool for helping to maintain output quality - like all other tools it might not work for everybody, or it might have to be applied carefully. But I wouldn't advise anyone to cargo cult the apostasy of a single proponent.
