Why is it difficult to finance public goods compared to private goods
A private good is the opposite of a public good. Public goods are generally open for all to use and consumption by one party does not deter another party's ability to use it. It is also not excludable; preventing the use of the good by another is not possible. Many public goods can be consumed at no cost.
Water fountains in public places would qualify as public goods, since they can be used by anyone and there is no reasonable possibility of it becoming fully used up. Public television received over the air and standard AM or FM local radio also qualify, as any number of people can watch of listen to the broadcast without affecting other people's ability to do so.