those people using Tor/VPN are hiding their real IPs, so theymos can't verify the origin of user
if the user logged from the same clear domain (non Tor/VPN) almost all his logtime, probably theymos would easily release the account
Im pretty sure theymos is pro-Tor and probably uses it himself, or a VPN. I mean, the guy is hated by a lot of people, like Roger Ver and others, basically all of /r/btc is after him, they want this site, they want the /r/bitcoin, I think they already tried doxing him, so yeah, it's only sane to use proxies in bitcoinland. The question is why the hell wouldn't you? I mean Tor is free, and again, as other people said, it has nothing to do with doing anything illegal, it's about protecting yourself from attackers, and assuming this forum doesn't have attackers is naive. They are after everything they can get, starting by your account.
The reason theymos and Cyrus take so long to recover accounts I doubt it has anything to do with IP's and more because they simply don't have the time to look at all the ever growing request and for some reason refuse to hire staff to recover people's accounts that delivered the required cryptographic proof. The whole point of Bitcoin and cryptography is to demonstrate proof of ownership via cryptography only.