I just want a little bit of logic, but I'll settle for avoiding food poisoning

Controls on Bravetti slow cooker

Normally with controls on any heating appliance in the kitchen the further you rotate the knob, the hotter it gets. But for some reason Bravetti has decided not to follow that practice.

Excerpt from Bravetti slow cooker user manual
Source: http://kitchen.manualsonline.com/manuals/mfg/bravetti/bkc203.html?p=1

I presume that the firm is afraid that people will not cook their food properly and thus use the "Keep Warm" setting to create a bacterial cesspool in their kitchen. Sounds yummy.