In my case, I work for an ISP -- althoug not my ISP -- and the "cloud server" is a small virtual guest (that I manage) in one of $work's facilities. Between $work and AT&T (my home ISP), who do you think I trust more?
Many people have very little choice when it comes to the ISP they use. By setting up a "cloud server", at least they get to decide who, i.e. which cloud provider, has access to their traffic -- and can switch between providers much easier and at any time they wish.
Many of the isps modify your stream - Verizon used to add a subscriber id (so anyone can track and correlate you despite your best effort). Comcast used to add their messages into incoming html.
Comcast connections are metered for most residential users. Additional costs are incurred after 1TB of transfer. Also, home uplinks are generally pretty slow, and the VPN will be bottlenecked by its up speed.
you should be aware that VPN traffic still goes toward your 1TB data cap... actually, it probably uses a tiny more data then if you were not using a VPN...
I think cookiecaper read your earlier message as "why don't you run the VPN endpoint in your home" rather than "why use a VPN at all if you're going to put the endpoint at a cloud service".
Many people have very little choice when it comes to the ISP they use. By setting up a "cloud server", at least they get to decide who, i.e. which cloud provider, has access to their traffic -- and can switch between providers much easier and at any time they wish.