Except they're not independant of one another. I'm sure the behind the scenes show DW: Confidnetial mentioned several times that the new show was considered a continuation. Previous incarnations of the Doctor from the 1963-1989, 95 era have been mentioned or seen. i.e. The Fifth Doctor in the minisode "Time Crash", and what about "The Day of the Doctor" where we see the current Doctor, eleven previous incarnations and one future. I don't get how they can spell it out any more clearly that this show continues on from the 1963-1989, 95 era.
As from a creative approach, I suspect an episode from 1983 would have a different creative approach to one from 1963. Times and tastes change and TV shows like anything must move with the times.