I'd say it's up to the individual. You could have acknowledged if you thought it might have helped but it's not mandatory to call - after all it is designed to be a "listening" service.
I do sometimes fly using a listening squawk only, if ATC are obviously very busy (as those large airports tend to be). The QNH and other relevant airfield details that would be given by ATC if you had called can be gleaned by listening to other transmissions, or via the ATIS broadcast. ATC can always call you if they thought it necessary.