"Mobile data always active" developer setting enabled by default

[runoono]

when I enable developer options, the option "Mobile data always active" is toggled on by default. I havent seen this enabled with other qualcomm based android devices, such blackberrys and samsungs etc. personal testing shows that there is no harm in disabling it however I still have questions about this feature Is this intended behavior? Why is this enabled? What are the pros and cons of having this enabled vs disabled?