Why do you use Ghash.io?

[bitmagi]

I'm not a miner, so I have no idea why anyone would invest their mining power in a central entity that stands to devalue bitcoin.  I have seen many posts where people express their concerns over ghash and it's threat to bitcoin.  But I haven't seen any posts where the apparent hordes of miners who use ghash explain their logic behind it.  As Ghash gets bigger, whether they plan to attack the network or not, many people are going to leave bitcoin due to the threat of centralization that they were trying to flee in the first place.  Many people will see Ghash as a classified project being carried out by some agency or they will see ghash as the weak link that can be co-opted by the banking industry to destroy bitcoin.  So what is the secret to using ghash?  I don't get it.