The reason people want to make mods in the OFP engine is that it allows for very much and is a very nice engine.
OFP has open landscapes and addons along with scripts can modify just about anything we can see and touch in the game.
That said this thread is in danger of going very off-topic, so I suggest that anyone who posts in it stay very close to the subject at hand, which is 'Why do we like to make mods for OFP' and nothing else.
Have a good day now, y'hear.