what you said is a different problem.

After returning the island, China did not take care the people. People died everywhere when Mao was in power.  The islanders were not the exceptions. I never heard the tiny island.  Even if it was given away, it just showed it was so tiny and unimportant at that time.  Think about Alaska, at that time, people in USA were against it and they think Russia got too much.  People should not use the current situation to judge what happened in the past.