> This is exactly what would have also happened if the water companies were not privatized

This clearly isn't always true and when it does happen the public has the ability to require the transparency from their government to catch it happening quickly and the ability to hold the elected officials responsible for it accountable by voting them out and replacing them. Private corporations don't allow the level of transparency the public needs and aren't accountable to the public either.

Maybe the government could work out some deal that gives the public the right to put webcams in every meeting/board room of the private company, force their bookkeeping to be published to the internet, allow the public to request internal email and other communications, require independent audits/reports, and grant the public the ability to fire and replace any and all employees or executives at the private company who fail to do their jobs, but even then you'd still have the problem that private companies demand extra money on top of what is required to do the job just to line their own pockets. Why should we accept that?