Swiss council to accept Bitcoin payments

I think he's worried that someone will break into their website and steal all the bitcoin. There could be no way to track down the offender, and no way to reverse the transfer.

You might say that security is the probability of a successful attack times the penalty. Maybe it's harder(less probability) to steal Bitcoin than to get your routing and checking account number and drain the account, but in the second case you call up the bank and get the money back(less penalty).

I don't know that 'Bitcoin is not a secure currency', but storing large quantities of Bitcoin is a security hazard the same way storing large quantities of gasoline, crude oil, and fireworks in your garage is. It makes sense to classify that as a security issue, since "The bad guys light a match in our garage" is an attack vector that needs consideration in the security policy.

If you keep the Bitcoin on an airgapped computer, require two technical personal for every interaction and document every step, install cameras on the premises to watch for intruders, ensure that any received "hot" Bitcoin is backed up to a separate secure "cold" facility using regular secure transfers, ensure that the Bitcoin is transferred daily to the machine and that the machine itself transfers it to a new address that nobody knows until its needed, and use one of those fancy 3-party transactions requiring the mayor to sign off on any withdrawal; then maybe it would all be secure.

Similarly, oil refineries do manage to process crude oil without burning down. I bet you the people who secure it are paid a lot.