Comment by jacquesm

Like everything else: it's fine in moderation. Newbies should practice clean code, everybody else gets to make their own decisions. Treating anything as dogma whether it is Clean Code, TDD, Agile or whatever is the flavor of madness of the day is going to lead to suboptimal outcomes. And they're also a great way to get rid of your most productive and knowledgeable team members.

So apply with caution and care and you'll be fine.