Blue water is groundwater (1/4) and you may be able to say the same thing about it. Some blue water comes from underground acquifiers, so pumping may be bad thing if you're pumping faster than it replenishes; others is pulled up by the root system so is completely natural.

8% is grey water, water required to flush fertilizer and other pollutants. That sounds bad, but it too is often part of the natural water cycle.

Most of the problematic water usage is caused by irrigation. Sugar cane & beet can and is produced without irrigation, but doing so requires more land usage and possibly extra fertilizer. In other words, it's a matter of trade-offs.