>Why attack servers?

Because you can connect to servers via their IP addresses, and they have open ports. Windows PCs sit behind NAT, so you can't really connect to them, although it may be possible to hack all the home routers then open up a gateway to attack the local machines.

Another reason I brought that up is because the internet servers are the infrastructure behind banking, flight system, communication, etc. So the impact could be far-reaching than to infect home computers.