It isn't, but you can't control mass hysteria (stupidity). It's like the malleability issue, everyone was completely hysteric about it when MtGox reported about it. Transaction malleability is still there but now you hear nobody about it (and it still isn't a big deal), this is just how mass psychology works. In a month from now Ghash will be back to 35-40% and everyone will be happy again, even though there is really no significant difference between a pool owning 51% of the hashrate or 30%.