'Orbits' are usually symptomatic of non-pilot ATCOs overcontrolling the visual circuit for commercial reasons and should be a last resort, rather than routine practice.
I'm going to semi-agree here - sometimes it's necessary for the integration of VFR v IFR traffic. (Strong winds especially - where you don't want the circuit extending too far downwind).
HOWEVER - it's not the preserve of ATCO's. I often get asked by pilots "Can I do an orbit for spacing" when just tweaking the circuit a little wider to fit in with the traffic (which they can see 9 times out of 10) would do the job quite nicely.
It's the age old problem of people flying from ATC airfields with little or no A/G or FISO airfield experience. They're not equipped to make the decision for themselves and how some are, I suspect, taught, doesn't help either. They expect to be nannied and not have to think!