This makes Java developer lazy in
implementing memory management.
No, it releases them to perform useful work.
And Garbage Collection is very
expensive.
Compared to what? Facts? Figures? You're about 20 years out of date with that remark. The take-up of Java alone effectively disproves that contention.
This might improves the performance of application.
Or not. Did you have some facts to adduce?
Then why not give them ability to destruct the objects?
Because it's not required?
