They were already there!
I think the point is that they would have been better off not bringing the hybrid and instead using a 2014 car with a Mercedes engine to instead do what every other team did and run aero development and test tyres.
However, this point only works with the benifit of hindsight. If they had turned up and run 100 laps with the Honda they would have gone home with a truck load of data worth its weight in gold.
All in all it was probably worth the risk as they will (hopefully) not lose a chunk of time with issues at the Pre Season tests. But when looked at on its own, I don't think anyone can say it wasn't a pretty disastrous test, and had a massive opportunity cost.