They consider it a security issue.  It is also the reason why you don't see any private planes flying around, even though they supposedly are letting people get licences to fly.

Helicopters tend to be much more expensive than planes (at least the lessons in Puerto Rico are). They also have a more limited range. I would guess that , security aside, if anyone wanted a "flying machine" most would opt for the airplane as it is usually cheaper and has a longer range.

Besides, with all the electric cables over the ground I would thing more than twice before boarding a helicopter.

The Chinese don't understand helicopters very well. They would rather the big fan was inside the cabin and not outside the cabin so it could keep them cool on hot days. 

Beijing Military District is part of a no-fly zone for helicopters, etc,. etc., anything private, etc., etc.  Someone once asked a question about skydiving in and over Beijing and it is for those very same reasons.

Helicopters would attract the air force and / or SAM's, I think that may have something to do with why their not widely seen.

i have not seen helicopters in Shanghai too.you can see helicopter in sky only in some important day.

You can't fly private aircraft over China.