Jesus christ I hold my Bitcoins more secure than these morons at these huge companies. Hand over your bitcoins to me because I'm more trustworthy than some crappy Web wallet
To be fair, Blockchain.info actually make a point of advertising the fact that private keys are generated client side. So if that's genuinely the case they don't hold funds at all, just provide a heavily packaged experience of using user held private keys with a web wallet interface. To what extent any of that method is secure is a different question ("not very" would be my assessment), but in theory, Blockchain.info users should be able to import their private keys into a different wallet they choose.
True, but if you're buying a new house and the previous owner keeps a key to get in do you really feel safe? Now what if you bought it from some start up company / faceless organization? I would want the locks changed (aka: make a new wallet) where only I would have access.
Actually now that I've said the analogy of a house blockchain.info is a lot like a house. Sure you have the key but there are lots of windows for people to get in