It’s either wilful disregard of correct technique or (more likely) getting too low due to the visual illusion caused by the upsloping runway.
In either case it is unsafe in the conventional aircraft operational sense, the approach should have been discontinued before crossing the coast.
As soon as you start departing from a standardised profile you are opening the door to any number of further threats and errors.
I have not flown into Skiathos but I have flown into plenty of Greek islands and other locations with short runways in turboprops and jets including various models of Airbus. FCTM technique every time, if the performance figures don’t work, you don’t fly the approach. What you do not do is start making up flying technique ad hoc - trust the FCTM, trust the performance figures, fly the correct technique every time.