Discussion on question by Maxim Gerasimov: Почему GC.Collect не собирает List помеченный как null?

Imported from a comment discussion on https://ru.stackoverflow.com/questions/1550162/%d0%9f%d0%be%d1%87%d0%b5%d0%bc%d1%83-gc-collect-%d0%bd%d0%b5-%d1%81%d0%be%d0%b1%d0%b8%d1%80%d0%b0%d0%b5%d1%82-list-%d0%bf%d0%be%d0%bc%d0%b5%d1%87%d0%b5%d0%bd%d0%bd%d1%8b%d0%b9-%d0%ba%d0%b0%d0%ba-null