I bought my Casascius coins because:
1. Secure off-line paper-wallet equivalent; cant be accessed over a network and I can put them in multiple locations.
2. I can give them to less technical friends/family.
3. Their value may be greater than face value in future.
4. I'm starting to trust bitcoin more than centralised banking as a place to store my money.
5. I collect weird currencies.
I've deliberately put half my bitcoins into Mike's coins for the above reasons. I would advise anyone to keep 50% of their coins off-line and if possible split into multiple sub set locations/devices for both on-line and off-line coins.
Doesn't Mike know the private key to all casascius coins he produced?
He could do, but I know where he lives and the addressees of his businesses which he has willingly given me as a customer. I trust mike to do as he says and destroy all the codes in my coins post production.
IMO it would be more effort and less profitable in the long term to scam people than to simply keep making physical coins and/or franchising his physical coin business.