Yeah the risk is pretty high, so as long as the bitcoin price is going up we will likely see people being happy with the mayor. But once there is another crash in the bitcoin market and the coin tanks, then there is likely a public outcry against him. For bitcoins is definitely a good thing as it makes more people aware of it and pushes the coin higher. The politcial career of the mayor might be linked to the bitcoin market now, a very risky move.
This is what I am concerned with. Even if he is having that intention to make the funds bigger, that won't force the market to be in favor of his intention. There's no assurance that profit will be earned and even if there is a chance, that is a bad idea because it will seem that he is deciding under his plans alone without considering whether his people will agree to that decision. Just thinking of someone using my money in gambling, which will make me mad at him. That's also not under Mayor's responsibility to do so. And I do agree that this will result to bad publicity no matter how we view his intentions with this one.
All major cities have investment funds, this is not abnormal. It would be quite risky to put public funds in such a speculative investment though. I also don't want the government gambling with public funds this way. Governments have enough problems balancing their budgets under the best conditions, putting assets in speculative investments is too risky.