Many times , domains are registered after just checking for availability and there is no way the registrant knows about the past history of the domain or why it has expired. If a registrant does not want a domain name, he or she do not pay the renewal fees and and let it expire. Any one who wants the domain name, pays the registrar the registration fees and is free to use it for their websites.
If anyone want a particular domain urgently for a website, they only have to ask the registrant who may sell it at a very affordable price.