Guy and Chilli seem to be missing an important distinction, between a piece of advice and an instruction.
There's a difference between a request to continue a climb based on TCAS and an instruction to go around. In the former case that Guy cites, the controller is clearly in the better position to make the judgement as to whether the climb should continue. The crew ask, and further climb is refused. The controller may be frustrated by the request, but the decision is made in the right place.
On an "unusual" approach, the controller may advise the crew of the anomaly, and West Coast has pointed out that he would welcome that. But I find it very hard to believe that a controller in the tower has the combination of information, expertise and experience on type to make a better decision than those on board the aircraft with the responsibility for its overall safety. The crew should make the decision. Once a go-around instruction is given, the controller has made that decision in place of the crew.
It's not a commercial issue, but a safety issue. Chilli writes:
Nobody ever got hurt from being sent around
but it's by no means an easy option. I've read with interest and horror the tales of minimal fuel reserves that seem to be the norm in some airline operations, and there is no shortage of incidents of pilots coming to grief in the go-around process. Sure it should be a normal procedure, but it's not without risk, and the assessment of that risk is the crew's job.
Crews make decisions that affect the safety of the aircraft frequently. The division of responsibility between flight crew and ATC is not the result of some treaty ending a long and bitter war between the parties -- it's that way because there's a well thought out and well tested balance of authority and responsibility. Trust it, as the crew trust you.