Staying clean is easier than getting clean.

For example, when you allow a single warning in your compile, it starts compounding.

Each incremental one isn't that much worse than the first, so you leave it.

The marginal rate compounds, because each additional one is less of a big deal than the ones that already exist.

Now you have a massive, confusing, distracting thicket you'll never get through without heroics.

If you simply never allowed the first one, it could have stayed clean.