"Unscrupulous winemakers still don't clean their equipment properly, and use bad fruit. So, as the saying goes, 'rubbish in, rubbish out.' But this wine still has to be sold."
You can read the whole article here. The point we like to take out of this is that while some bacteria and microbes are beneficial to your wine, others are not. We know, it's not revolutionary stuff, but the point of cleaning and hygiene is to control for the bad stuff, whilst still maintaining the good stuff.