Here's why:
* Safety: Lack of windows significantly reduces protection from the elements (rain, wind, debris, insects) and reduces visibility, especially in bad weather. This greatly increases the risk of accidents.
* Legality: Depending on your location, driving without windows might be illegal. Many jurisdictions require functional windows for safety and emissions reasons.
* Comfort: Driving without windows is uncomfortable and unpleasant, especially at higher speeds. You'll be exposed to wind, noise, and debris.
While removing the windows is a common feature for off-road enthusiasts, it should only be done in appropriate conditions and for short periods. Always reinstall the windows before driving on public roads.