Would you allow your young children/grandchildren to fly on an airline that thought it OK to continue longhaul....as BA reportedly did....after an engine failure at 100 feet?
Would you be comfortable with them flying the 5000 miles the A380 completed on 3 engines as reported here?
Just SLF here, but I suggest that many professionals would be happy following their planned course, particularly if it passed close to potential landing sites with appropriate engineering support, rather than flying in circles near the take-off point burning and dumping fuel to get down to a reasonable landing weight.
If the remaining engines are performing well and are giving no indication of iminent failure and all parameters are comfortably within normal range, why take the risk of an overweight landing?