I dont think definition creep is an acceptable reason to merge grilling and BBQ  The fact that individuals use the term incorrectly and grilling is not BBQ so using them interchangeably is incorrect is not a reason to use it incorrectly in this article  I believe the confusion comes from BBQ grills which have the capability to both grill and BBQ  That does not make the processes the same it just means that individuals have integrated the two terms for ease of use