Well, that's a common IO behavior from many countries around the world. The DTV doesn't protect you from any questions or check on the purposes of your stay unfortunately.
The ask:thailand community, consisting of multiple Q/A groups with over 100,000 members, powers this platform. It is not an official government resource. Our members actively contribute to this resource, and while we strive for accuracy, we cannot guarantee its complete reliability. Assistance to travelers is provided as a community service.