No need to go on about these people. It's my opinion
Yes you are correct if the hackers hack someones Bitcoin then it will be sell by them very faster so it will not helpful for the development of anything and they don't hold it for much more longer time this will leads to the way of not carry Bitcoin
Hackers are not that dumb. If these hackers hack someone's Bitcoins and immediately sell that, the owner can track that certain hacker. As I said, hackers are not that dump,before selling it, they might just hold it for a while and send it to other wallet that the owner don't know or can't track. We have Blockchain.info so we can track our wallets transactions.