Interesting question...personally it is a hindrance...but is the only way I am familiar with other than my own personal library which is strictly alpha by subject area.
Dewey's system is out of date. There are subjects new and popular to the world which were not around when Dewey was. Computers, for example. This forces huge subject areas into tiny fractions of a value.
I'm a computing student. I don't know why the computing library bothers recording whole numbers any more. They might as well start from .001 and stop at .998 (I've never found .99, most odd).
So, I vote: hindrance.
(But not such a hindrance as enraged elephants with a trunk-machine gun, though)