Bandwidth is not free. Every time a page with a linked photo is loaded, bandwidth is used. People do not work for free. Keeping a hosting company operating requires people to work there. Electricity is not free. Keeping servers working to be available when you want to access a file needs electricity.
I am always amazed by the outrage when something is not free. Even if it used to be free, you should have no expectation that it remains that way. Read the terms of service when you sign up for a "free account". First is that terms can be changed at anytime without notice. Second, you give up many rights to what you are doing. For instance, by signing up for TB, I have given up my copyright to what I write here. The rule of thumb is if something is free, it is very likely that YOU are the product; which is to say, if the service is free, in all probability information about you is being sold to someone else.
If there is no profit available, you will find that there is no service available. Consider your bands - would you pay to play in venues? You provide the service of live music and assume that you will get paid for that. There are very few that will absorb the costs of providing a service of any kind without expecting to get paid for the provision of that service.
For what it is worth, I pay for not only my internet service, but also for email and online storage. Some of you may think me a sucker for doing so, however, it substantially changes the contractual arrangement in my favour. I wouldn't have it any other way. I give up no rights to the contents of my email or files.
Will photobucket go out of business because of this? Who knows, but if they can't generate enough revenue to cover the costs of operating, that would have happened regardless.