Re: Isn't cloud lovely
Lets look at the alternative - on-premise systems.
You install you on-premise Exchange system. In 7 years time (or less depending when you installed it) it reaches end of life and you should replace it. You don't, because you are in control.
Two to three years later, you have a number of security issues, you end up using a third-party to provide additional security that stops working with your end-of-life environment and suddenly you have OS/Application/Client upgrades in one massive, expensive hit. All to do the things you refused to do in a timely fashion when you had choice. Add in a few security scares that necessitate significant effort to address (i.e. downtime for patching or new systems to provide missing functionality) and the end-user experience can quickly turn sour.
Cloud is the other extreme - change happens very quickly and is often difficult to keep up with if you have a significant amount of integration between business systems. But I believe the cloud approach is more manageable for most businesses over a medium to long time period. And users see a system that mostly works 24/7 rather than one that always works 8x5 until it doesn't.