Quick dis-connector serves a couple functions:
1. You can swap different equipment to use the same natural gas pipe. Not only you may have an outdoor stir frying stove, you might have a grill.
2. Once you are done with cooking, you can disconnect the stove completely from the gas line. This might give you peace of mind that nothing is leaking.
The non quick dis-connector option, i.e., an EF11LN50WG stove connects to the gas line permanently.