Methodological issues are usually good issues, because they are easy to spot. Here the issues are more about the data itself. If you use perfect methodology and put garbage in, you still get garbage out.
Politicians often make the mistake of assuming that if they do something in order to get X, the outcome will be X. Researchers who are more familiar with the methodology than the subject matter often make similar mistakes. The data that is supposed to measure X never actually measures X. It measures something related but subtly different. If you want to make conclusions from the data, you need to understand those differences. You need to understand what the data is exactly and the process how it was collected. Including the details you think are irrelevant but aren't. The last part is particularly problematic for people who are not subject matter experts.
Politicians often make the mistake of assuming that if they do something in order to get X, the outcome will be X. Researchers who are more familiar with the methodology than the subject matter often make similar mistakes. The data that is supposed to measure X never actually measures X. It measures something related but subtly different. If you want to make conclusions from the data, you need to understand those differences. You need to understand what the data is exactly and the process how it was collected. Including the details you think are irrelevant but aren't. The last part is particularly problematic for people who are not subject matter experts.