I'd been under the impression that engine designs early in their lifecycle tended to have these kinds of problems, as even the best testing will never fully replicate real-life conditions.
While it's only right that RR should look into this in as much depth as is humanly possible, I think a lot of the opprobrium directed at them is a little excessive. Specifically my mind wanders back to the CFM56-3C-1 and it's teething troubles - another derived and uprated design that suffered multiple failures which in one case led to a nasty accident (Kegworth).