In my opinion, division of any state is not really good in any aspect. More states mean more ministers which may lead to more politics and more curruption. Division is no solution for better management.
There are other states in our country which may not be as big as UP in both area and population but are still big enough to challenge the administration. Still, they are administered and governed in a pretty good way, like Gujrat.
Also, if we look at United States of America, before being known as one country - the USA, they were around 50 small countries with different administration which lead to wars, chaos and a haphazard management. Later these states were united and came under one administration. Today, U.S.A. is the most developed country of the world.
Nothing needs to be said further.