Originally posted by kyrellic
The 2da's were compiled, etc. to make it more difficult to modify.
Going off-topic here --
Actually, I doubt that was the reason the 2DAs were compiled. The V2.b files are much smaller than their V2.0 counterparts by taking into account repeating values. Appearance.2da for example is <1/5 the size. Smaller files usually translate into faster gameplay.