Which is exactly the point. Healthy skepticism is not bad. But look at both sides of the picture. Do not automatically dismiss a study because of where some of the funds came from. Just keep an open mind. And science is generally not based on one study alone but the replication of research findings by other independent research groups.
So the authors of the original article that I cited came to the following conclusions:
However, the one thing that the authors cannot overcome is the fact that food frequency questionnaires (FFQs) are notoriously unreliable. People regularly underreport how much alcohol they consume, for instance. I barely remember what I ate for lunch, and that was just a few hours ago. There's simply no good way to get around this shortcoming, though the fact that the authors detected something of a dose-response (i.e., the more artificial sweeteners a person consumed, the less likely he or she was to develop cancer) strengthens their case.
Additionally, there is the nagging issue of confounding. People who drink artificially sweetened beverages may have other health habits that are responsible for lowering the recurrence of cancer. Perhaps people who drink more Diet Coke also eat more celery. The authors did their best to adjust for such confounding, but there's always the possibility that something goes undetected.
Overall, I find the result interesting but unconvincing. If artificial sweeteners really do decrease the recurrence of cancer by more than 20%, then they should begin a clinical trial pronto.
That is why I thought the authors of the article presented a well balanced article. And also their conclusion was to target more research to prove whether these findings were real or due to other confound issues.