"Be professional" would be a better aim.

In my opinion, the most important thing for code is for the developers to actually care about it. Whether you test first, test later, or just simplify the code until it's obviously correct [1] it really doesn't matter, just care enough to want bug free software.

[1] "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." (Tony Hoare)