It is merely a well worn path that they will all follow. As long as you recognise it, you can opt out. Evil implies immoral intent to cause harm or pain. Whether it is immoral or not to start adding tiers to squeeze more out of you to prevent you slipping down the service tier you get, is up for debate. I'd lean toward it errs on the side of greed although not to cause harm or pain. - a religious man might call greed immoral though?