The fact is that the scoring refinements over the years have made gymnastics much less subjective than they've been in the past. Start value minus deductions means the pressure to award "perfect 10s" is gone and the judges can critique each routine on its own without having to worry about having to balance difficulty vs. execution; they're now focused solely on execution, with difficulty already factored in.
Of course, you still have the chance for getting a biased/crooked judge, but there's only a handful of sports that can operate with no subjective officiating, and those come down to raw timing and accuracy events.
College Football is subjective, too.