Because the linked research does not support the point the poster is making. The researchers did not find a link with dishwasher detergents. They found a link with rinse aids, but at quantities and concentrations far higher than you'd find in a dishwasher.
Also, I think we should all be skeptical of someone who says, essentially, "Don't want colorectal cancer? Rinse your dishes and don't eat at restaurants!" Such a simple explanation for colorectal cancer seems suspicious... at best.
This rapid increase is especially puzzling because the rate of colorectal cancer has plummeted among older adults—largely due to regular colonoscopies and lower rates of smoking.
“We don’t understand a lot about the causes, the biology, or how to prevent early onset of the disease,” said Phil Daschner, a program director in NCI’s Division of Cancer Biology. “And that’s important to learn more about because it may affect [approaches for] the treatment and survivorship of early-onset colon cancer.”
