It's no more far-fetched than they spending astronomical amount of money to attack a PoS system (and without guaranteed success, like attacking a PoW).
Okay - am coming around to your point of view now - but one point still bothers me which is the *hacking point*.
With PoW you can't *hack the proof* you have to "do the work" (unless a fundamental flaw is found with SHA256 which would probably screw up all cryptos that exist at the moment).
It may be much easier to *attack the wallets* of stake holders (via keyloggers, etc.) in order to gain the stake without having to spend "astronomic amounts" of money.
I'd argue PoS miners are much more security minded, since they have to pretty much keep the wallet hot (online), even if briefly, in order to mine with it (though I believe in DPoS system you don't have to, since mining is delegated to the delegates, you can put your funds in cold storage). Also they are very much de-centralized, instead of concentrated in a pool, can you imagine how hard it is to obtain the identity of 10,000 PoS miner, their IP address, and then some how access their mining PC etc...
I'd be much more worried that discus fish and ghash.io getting hacked simultaneously (imho a much more likely scenario) and the attacker instantly gain 51% in Bitcoin.
Keeping your wallet "hot" by definition is going to make your funds vulnerable. If any PoS coin ever had any meaningful market cap then the miners would be under constant attack, likely to the point they would choose to no longer mine and exit ownership of the coin.
Not really, you will only get constantly attacked if you are running a website with the hot wallet.
If your PC is not running any service, not install any trojan/virus, and the network is properly firewalled, the chances of getting hacked, is practically zero. If it were that easy to hack someone, no one would be using Bitcoin anymore, since majority of the Bitcoin users are not using cold wallets neither, and the average Bitcoin user is much less security minded than a PoS miner, who probably has taken the correct security measures to keep his PoS mining PC safe. Plus the hacker would only be able to obtain an encrypted wallet, that he then have to try to crack, probably a fruitless effort.
Usually a Bitcoin user gets hacked due to 1. unencrypted wallet, 2. backs up wallet + password in the sameplace (ie dropbox), and account gets hacked. 3. installed wallet stealing malware, and password got keylogged.
Non of these will happen to a correctly set up PoS miner.
So you need a dedicated computer and internet connection to mine in a PoS schema? Isn't that trending back towards the whole "wasteful resources" thing? Certainly not using gobs of electricity, but it does dictate a hardware requirement of sorts.